I found a (barely RTA-viable) setup for the clip in -2. It saves 3 framerules over the normal FPG and is only 1 framerule slower than HappyLee's TAS.
I made a video in which I explain how to retime runs in the category "10 Lives". It's not very intuitive how the game behaves during the infinite 1-up trick, so it took me some time to understand what's going on. The reason I looked into this is because Roy's WR has been retimed incorrectly. Following the way to retime runs that I propose in the video, the WR should be a 1:28.504. My current PB (not yet verified) should be 3 frames slower (1:28.554, I retimed it in a different/wrong way when I submitted it).
I found a setup for 1-2 FPG that is similar to the one in 1-1. It might be useful for warpless runs. Just like in 1-1, you have to land on the 6th step, but on the second rather than the first pixel. Furthermore, the setup requires slightly different inputs. In 1-1, the inputs for the four frames while/after landing are right right + B right + B right + A + B For the 1-2 setup, you need to press right right right + B right + A + B So only one frame is different. The inputs for the clip are the same as in 1-1. Here is a video of me doing 1-2 FPG in an RTA: