Hmm.... After using ISOM and able to use square tile terrain, I was hoping to reverse it so that it turns back into the old starcraft diamond shape terrain.
It kinda sucks if you can't though.

No, you can't. You can try SCMdraft 2.0, they can reverse it sort if.
You mean like it adds something else weird like another tile right...?
Well I'll try using that to see what happens.
No, no SCMdraft 2.0 (( posted in general staredit forum )) has 3 different brushes (( square, diamond, rectangular )). Diamond is normal, rectangular is like isom only easier to place and square is what you get in guedit and starforge.
Edit: Here it is anywayz.
**Note: This is only a beta so it isn't fully functional**
SCMDraft II, as an editor, to me... is hilarious. All the units are spinning and dying and stuff.

Yah it's humrous but it works.
Yet it still contains major bugs! Its a Terrain Creators friend, SCMDRAFT 1.0 Beta is da Cool Editors friend! So many hidden options!