What can be done to make a Bsp conversion smaller

[bumlove]

I trying to convert delta tower 03 I tried gemini as a base but that wouldn't work (don't know why it just didn't load (3 attempts))
I then got it to work with colossus as the base but some thing was/ is screwed up with the obstical (bloc) pallet or placement where most stuff just didn't show up and the stuff that did show up kept respawning on top of its self, any way I didn't see that as too bad a problem I figure make these magically respawning blocs fusion coils but It seams it is a problem
("blah blah blah some huge number is not right for a start" in the scnr tag) now I've done things in different orders and the first things I do always work it all seams to break down when I get to the magical 90MB mark (its a big bsp theres at least 3 big playable areas and 2 areas for my more unusual taste in gaming) does nulling stuff out make space?

Im trying conversion again this time I'm ticking nothing except mach (I have to due to see thru bits of the bsp)

how can I make/save space?

Also is there any version of entity or any other program that allows you to deleted chunks in groups (shift or control) you can do it for ident swapping but not for chunk deletion as far as I can see