Ceiling slam

Ah yeah, there is no pre-existing event-code related for stats, that would have to be coded in assembly first and THEN used in the event code.
In other words, you'd need to code the custom command first, then apply it to one of the unused event commands so you could use it as a check via event code... I hope this makes sense, I'm definitely not the best to explain it because I am an assembly noob lol. But I know of similar approaches others have done utilizing event commands in tandem with assembly code to achieve things dealing with character stats and statuses etc.

So basically, you would code your custom 255 stat check in assembly, in C0 I'd imagine, and then use an unused event command from the General Actions' Jump Table at C098C4, and repoint it to your custom assembly code. You can tell which event commands are unused because they have a pointer of 1AB9, which points to an RTS.