People seem to forget that there are 68000 systems that are much faster than the proposed "bottom line" of A1200 with 020. Anyways, both 68000 and 68020+ can easily be supported, this is AROS, not OS3.9 - there _will_ be 68000 support, whether you like it or not
Btw - PeterK's icon.library works excellent on 68000 (also with AROS) - but it is assembler, not portable C.