Original plan had us get invincible after the miniboss. This was because said plan originally attacked miniboss with giant laser, which has the side-effect of removing invincibility. We don't apply giant laser on miniboss anymore (thanks to skip), therefore doing the invincibility trick before it means we won't promptly lose it on our way through the miniboss room. So, while waiting for skip to become possible, set up invincibility.
These ceilings on the upward segment are giving me a lot of trouble, which is why I haven't uploaded a completed Stage 7.