All Doctor Mario costumes have been changed to the Legacy XP model.
All animations have Coat & Stethoscope physics (ported from Legacy XP, some edited, some brand new)
Two unique Idle Animations (not the main one because of PSA problems)
Unique Entry animation + recreated Pill Entry from Ultimate.
One unique Taunt animation (Thinking instead of Removing Hat)
Two unique Victory animations (Throw Pills, Play with Stethoscope)
Flash White instead of Red during Neutral Special.
Sparkle GFX added to Neutral Special to be more like Ultimate.
Pill model from Legacy XP (Lower Quality for File Size purposes)
Legacy XP's Viruses appear instead of Coins during Up Special (Blue has a darker texture)
Side Smash has different Lightning GFX.
Legacy XP's Final Smash ported and modified to be closer to Smash 4 & Ultimate.
New Pill Sounds from Ultimate have been added.
New Mario voice clip added from Mario & Luigi: Superstar Saga + Bowser's Minions.
Pill Hit Sound used for Up Special & Final Smash to make them more unique.
Cape is now Lower Quality for File Size Purposes.

Up Special's first frame of animation has been changed so Mario doesn't have his feet on the ground, and then both the Ground & Air versions use the same animation. This results in minisule differences but differences non-less for Competitive play. This change was made so SpecialAirHi could be removed to reduce File Size.

MOVESET DIFFERENCES:

The Regular Moveset has all the above changes but the actual attacks are kept the same for Competitive purposes, besides the Up Special change of course.
The new animations make this Desync-Wifi & by default not Tournament-Legal but maybe could be argued?
IDK, I don't actually care about the Competitive scene so whether or not this gets used doesn't matter to me.

The Modified Moveset has all the above changes but also the following changes to the Doctor Mario costumes:
Down-Air & Back Throw are recreations of Ultimate's versions.
Forward-Air's sweetspot no longer Spikes and does 20 instead of 15 Damage.
Down Special has been reworked a bit so both the Ground & Air versions use the same animation for the actual attack but then change to different Ending animations, freeing up space for the 2 new additional attacks.

I did not include this change in the Regular Moveset for fear of messing too much with the Competitive aspect. While I didn't notice a difference during gameplay, on a technical level the attack switches to a new Action for the ending which may or may not mess with Competitive play. Like I said, I'm not big into the Competitive scene so just because I didn't notice a difference doesn't mean there isn't a small difference. The point of the Regular Moveset is to keep it as close as possible to the original Tournament-Legal movesets, since I didn't need the extra decrease in File Size, no point in making such a big technical change to one of the attacks.

MODEL INFO:

FitMario.pac no longer has Fireball & Pill models that are used for various animations.
FitMarioEntry.pac has an "empty" model where both the regular & shadow models have a single polygon that has all its vertices at (0,0,0)
The actual models used for the Entry are in Article 2 (F.L.U.D.D) inside each FitMarioXX.pac & .pcs files.
Article 2 also has models used for the Down Taunt instead of it using models inside the FitMario.pac file.
Article 1 (Fireball) now contains both the Fireball & Pill models as well as the Cape model from Article 0.
Article 0 Redirects (Reuses) the model file for Article 1, the texture file is still inside the FitMarioXX files, which is Redirected to Article 2's texture file.
Doctor Mario's 2nd Victory animation (Throw Pills) now uses Articles 0 & 2 instead of models inside the FitMario.pac

COSTUME SLOTS 30 - 39:

In the Project+ versions of this mod, Builder Mario was also given some unique changes.
Despite not having Builder Mario by default, this version does contain the same changes.
The BrawlEx version requires no editing except the actual Costume Count, Non-BrawlEx builds will need to the FitMario.pac to be edited to change which Costume Slots use Builder Mario's changes.

The Builder Mario Costumes are a combination of the Regular & Doctor Mario Costumes, mostly being Regular Mario.
Builder Mario now uses a Hammer instead of a Fireball for everything except the Final Smash.
Each Builder Mario costume has his own Hammer colors.
Builder Mario flashes Dark Grey during Neutral Special.
Builder Mario has Doctor Mario's 2nd Victory animation but with Hammers instead of Pills.
Hammer sound ported from King Dedede's soundbank.

NON-BRAWLEX VERSIONS:

All Costumes use the same FitMarioMotionEtc.pac and FitMarioFinal.pac files.
This means that they share a Combo-Final Smash file that contains both the Fire & Pill GFX, which has a much larger File Size. However no Fire is left behind on the stage as it would also happen with the Pill GFX.
The Articles 0 & 1 models are shared between all Costumes, so only one set of Fireballs and Pills. Hammer model is instead located inside the FitMario.pac with copies for 10 Costumes (Only first 3 are used by default)

BRAWLEX VERSIONS:

In the Individual Files folder you'll find an edited Fighter Config file that gives each costume their own FitMarioEtc.pac and FitMarioFinal.pac files.
This allows for more customization as each costume will have their own Fireball/Pill/Hammer models instead of having to share with each other, meaning each costume can have their own color variation or even custom model.
Hammer model is located in Articles 0 & 1 instead of the FitMario.pac.
FitMarioEntry.pac is removed entirely.
The Fire version of the Final Smash does leave Fire behind on the stage.

PROJECT+ + BRAWLEX:

There is currently a BrawlEx Build of Project+ in development, however it currently does not have a release date so for the time being, the Project+ version of this mod will only work with Project+ v2.15 & v2.2
This means that only 1 FitMarioFinal.pac & FitMarioMotionEtc.pac can be used.
I have included all the Files that will be needed for the BrawlEx version anyways because they do work perfectly in Project M, except for the Fighter Config file as I don't have access to the Project+ version.
When the BrawlEx Build does eventually release, I will update this mod to include the Fighter Config file as well as any possible changes that are needed to be compatible.