Using add36k & 21k sadly doesn't mean you'll get 57kb more.
They both (&add44k, too) simply reduce f.e. the used colors on screen to
b/w which gives you some kb chip. Alternaively you can start
add44k twice. The prob is, that the rad-device screen anyway only uses
4 colors (?), so you won't get much more mem...
Really not very sure about this, but aren't there some progs in aminet which can "defrag" free mem, so the biggest-memblock will get bigger?
Maybe the combination
could help with some games, too...