The hack includes tables and adds to calcloops, you should read SME’s installation instructions for more details. As an example to help you through the instructions, reference the github buildfile of the only hack that used Laguz Bars, Endless Nights. It didn’t ever really use the transforming though, as your playable Mauthe Doogs in the 2-chapter demo are permanently halfshifted like Volug.
You should check the files in the github to see what Thor Studios edited in each file SME specifies in the instructions. Don’t forget to add the meter to Modular Stat Screen. MSS is the reason I think 7743 never made a FEBuilder Patch. The other of SME’s hacks that uses MSS, Holy Blood, is not a patch either. Good luck if you want to install the latter, though, as the instructions are even more cryptic and nobody’s ever used it so you have no reference.
I know so much on this topic as I tried to use these SME hacks on a cancelled project of mine, which was going to have recurring cameo Larabel/Aimee as the protagonist and a dancer. In her starting party would have been a Kitsune which used Laguz Bars and is the reason I ported the Selkie anims from Fates & Heroes, which you can still find on the Repo.