im pretty sure this is the smallest entire map filler, its only 8 blocks!
V3;1g;1g;{(0(RB)ii0(1f(1d)0(1e(1e){SS(1g(1f)(0(Ql);;;0
this is a fast nuke:
V3;1P;1P;{(0(1qj)Ai)gfi0(1O(3b))0g(1O(1y)ASi)1d0(1O(1z)(1N)ei(1O(1A)SS(1N)bS(3r(3g)i0(1L)7Ai(3r(1F)0(57)6S)b5(a9(1B)i0SSSiSSSAi(a9(1D))86S(fd)8(1O(1y)(1G)7)09S(1O(4Z)(0(1dh);;;0