In Creately classic a user could setup Page size in document settings (either custom or for A3-4-5 etc with different orientation). This way I never would make bigger diagrams than needed. It was an essential limit of working space.
New version lacks it and it makes it unusable because you always can “draw” beyond limit and fixing it is incredibly painful (been there, done that, never want to go back). It’s critical feature, deal maker or breaker.