Hi cocomut, I’m sorry to hear about your crashing issues.
As smithy285 pointed out, I’ve tried to include several possible ways of preventing players from crashing your server. Depending on your gamemode, some options are more viable than others. For sandbox, not much can be done.
You could try to lower the max count (max stacker entities they can create at one time) and increasing the delay (how quickly they can use stacker). It won’t ultimately stop crashes, but it will give you more time to detect and prevent someone from crashing the server (given that you and/or your admins have a mod to show who is spawning props).
Forcing the props to be no-collided helps somewhat in that all of the stacked entities they create per stack won’t cause any lag by being unfrozen. However, each stack of entities will still collide with others, so it won’t stop crashes either. You may also find yourself running out of non-networkable constraint slots or whatever (due to the high number of nocollide constraints being created per stack).
I’ve contemplated making the stacked props spawn over time like AdvDupe 1 and 2, though I admittedly haven’t explored it very much due to the added complexity. It’s really one of the few ideas I have left to try and help prevent crashes, but it’s truly difficult to find a good solution given how the tool needs to work.
Unfortunately, gonzalolog, clamping the minimum distance won’t stop crashes either since they can just continually stack 2 or more props inside of each other and then unfreeze it. The effect won’t be as immediate as if they had just stacked them all inside a single prop, but it will still easily crash a server.