You're right, but if I were playing devil's advocate, it could be argued that by "not supporting incest" they mean the script doesn't workBecause it's against Patreons terms of service. So he either makes money or doesnt... It's not hard to work out
Tons of other games you DL a patch and your landlady becomes your mom, roommate your sister, etc. But while it CAN work, the way the game's written Chloe being your sister and Heather being your mom just doesn't work the same as it did in ToN or even Lust Epidemic
And you're right, patreon's got strict rules about this stuff, it just seems odd that this game seemed written in a way where an incest patch just wouldn't work