Couldn't the incest patch be reworked to replace lines of dialogue rather than scene labels, similar to the way the Summertime Saga patch works? There's a couple of places (the shower scene and the therapist scene) where you'd need more than that, but it should be possible to write a detector for if the walkthrough mod is installed, then load appropriate replacement scenes if so.
Disclaimer: I haven't read the code for either mod, so forgive me if I'm talking out of my ass here.
About the disclaimer, don't worry, it's fine.
But the incest patch does not touch any scene labels at all, it only chances dialogues, in a couple of occasions the value of a variable, and in one occasion adds a choice to the menu (the therapist, as you correctly identified), but again, I did it without changing scene labels and the flow.
The trick is that I replace parts (not even entire phrases) of dialogue in a way to keep coherence with the original (before Patreon's intervention) storyline as Zorlun had indicated it at the time I discovered the game, but as far as I recall, the WT mod also modifies the script, by adding up references that are then replaced by using an extra file, to give the indication of the path to follow.
So, both modify the script.
Also, I do not replace scenes, I use the ones existing, and in any case, you are hitting again on the fact to guarantee compatibilty with all possibilities, it would mean either I or the author of the WT mod (sorry, bad memory for names) would need to use the mod of the other as base, and then create two version of their mod.
Right now, I can just take the code of the new version from Zorlun, get the added part to the previous one, add it to my patch and modify it to be aligned with the incest part - safe for that extra choice with the therapist and an occasional variable value change, my code is aligned with the one from Zorlun.
Doing the kind of "detection" you are mentioning (I guess you mean it as avoiding the need for two versions of the patch), would require me to do some coding, that would lose the alignment with Zorlun, and make it extra complex - I do not have time for engaging myself on that type of programming, sorry, the actual form of the incest patch is as far as I can go.
Effectively, bibfoc does detect my patch, for the compatibiliity with his "name changing mod", he only looks if there is a variable set, because I created an extra variable that he detects, but even that, I did not create modifying Zorlun's code, I leveraged Ren'py characteristics, creating a small extra file that only defines the variable bibfoc detects.
Last but not least, because Zorlun had to modify things "on the fly", and it had never foreseen to have to take out the incest part, I cannot even though just a blind keyword replace, e.g. even in the incest patch, "Mi" can be "Mi" or "mom" depending on the situation.
