TCE's source Artificer file contains both official and UA 3rd level subclass features.

[GarnetSan]

The "TashasCauldronOfEverything/class-artificer-tce.xml" file has the official subclasses right, but whoever wrote the file also added the 3rd level Alchemist, Artillerist and Battle Master subclass features from UA's Artificer and Artificer(Revisited).
For example:

• Lines 378 through 432 hold the Artificer(Revisited)'s version of the Artillerist 3rd level features, with Arcane Turrets and such instead of the official Eldritch Cannon.
• Lines 193 through 250 hold both the Artificer(UA) and Artificer(Revisited) versions of the Alchemist, with Extra Alchemical Formula and Alchemical Homunculus.