Is it acceptable to use huge ships in any missions because it is technically not 100 point standard play?

or can you only use them in missions that already include huge ships (like running a GR-75 in one of the missions that came with the CR-90)?

or can you not use them at all, unless the mission specifically says it is part of your force?

Any ideas? Thanks.

It's entirely up to you at the end of the day. But they are supposed to be fielded only in Epic Play. Make some scenarios up that incorporate them.