No crashes, just incorrect behaviour.
With the option enabled, attempting to sneak past Sculk Sensors will instead trigger them, breaking their whole sound-based sneak mechanic.
Reproduced with only Fabrication and Fabric API using vanilla Sculk Sensors, but it also affects mods using the sculk system, like the recent Sculk Worm mod, and presumably the future Warden and Deep Dark.

unless una says otherwise, working as inteded.
feel free to make a feature request with an identical function that won't do this though

It breaks an advertised, intentional, vanilla feature, though. Especially when the Deep Dark comes out, if this feature remains unchanged, the entire stealth system will be useless.

and therefore there should be a new feature that doesn't do that.
which you can turn on instead of this one which is meant to "break the entire stealth system"

At the very least, maybe this feature shouldn't be on by default?

Considering it is in the tweaks category; it should not break an entire vanilla mechanic. Either move it to balance/weird tweaks or patch it so sculk sensors do not get triggered, please.