Can my custom domain be flagged if I use an email alias service?

Not sure if this is a real concern or not but I have a custom domain that I currently manage in proton. I think it makes more sense for me to use an alias provider but I can’t help worry that the domain itself may get flagged as one that provides aliases if I do.

The closest I’ve heard of this is github checking mx records and blocking accounts if they use one of these services. That at least is temporary though, I imagine getting on those annoying disposable/alias domain lists would be much harder to get off though and I use my custom domain for everything.

Is this a reasonable concern? Has it it happened to anyone?

Thanks