Your first example, or anything like
:org 0x210
0xAB 0xCD
:org 0x200
: main
loop again
Should work now.
I corrected a flaw in the assembler; give it another shot. It doesn't actually stem from any sort of implicit :org, but rather the fact that the "main" label is special. For programmer convenience, Octo will reserve space for a jump instruction at 0x200 to branch forward to main if it is not the first label defined in the program. Once you start re-orging things this gets a little fiddly, and it broke some assumptions I made very early in Octo's history. It would have worked fine if anything *except* main was the first definition in code-space, but now you can have those precious two bytes back.