A hack - by definition - is making your hardware do something that wasn't intended by the developers.
So, all trapdoor expansions larger than 512 KB (A500) or 1 MB (A500+) are hacks. They require an adapter fitted to Gary (changing system logic) and running a cable from it to the trapdoor card (for the additional address lines). The additional RAM beyond the 'official' size is always Slow aka Pseudo Fast RAM (=slow as Chipmem but not usable as such).
No hack is modifying a previously 512 KB Chip / 512 KB Slow mem motherboard to 1 MB Chipmem (by replacing Agnus and changing two jumpers). It's a simple mod that was largely intended by the developers.