Some bosses can be shortened considerable via solar flare (Goliath and healthbar1/phase2 minos cannon, primarily).

Many others simply have attacks that waste your time (stage 2, stage 4, stage 6). Has anyone found a reliable way to kill those peskier, time wasting bosses within just a few cycles? Stage 2 and 4 in particular are annoying because they spend so much time being inaccessible or invulnerable.

The only few damage-increases I've found so far are solar flare for multi-body enemies and blazing fist for enemies that stay slow enough to be hit (but then it has significant cooldown, and stops if you are hit during startup).