So i started a run with several of your mods, and this one is the second one in frequeny of it being the "annoyance", (in a real fun way), i'm using the settings "1 per side" because i wasn't sure i could understand the others from the settings page, and i didn't thought of looking at the mod pictures again when doing the settings. With the others mods for the game there was like 5 pages of settings.
It's really well done, the sound and the message that tell you why you can't place the inserter. And it makes really interesting challenge in the game all the builds look different, and it force me to change my habits a lot.
However ! one of my habits is to use the mod picker dolly, to move inserters to another tile after they were built. I notice it allow to "cheat" when it happened that an assembly machine i placed couldn't be replaced by a tier 2, and when looking at the hole created when i clicked i realized i was prevented to replace the assembly because one side had 2 inserters already. I know the mod picker dolly allow other mod to be compatible, something about registering an event or listening, but i don't know how to or if it's doable with your mod.
I suppose the hard minimum is 2 inserter per machine using sushi belts or combinators, one for input and one for output, so the mod is "beatable" in theory no need to cheat anyway :)