I'm currently working on a new Fire 'N Ice any% TAS, so far I've finished the first 4 worlds. You can see the TASes of each world I've done so far in this playlist:
https://www.youtube.com/playlist?list=PLtB93KMjqMCLFrKLbIz_gDD3JlrQtzzk6 (fyi I redid some worlds due to finding optimizations, but the newest uploads are pretty much all up to date, except I found a 0.317 second time save in 4-10, that I didn't upload, so world 4 is 5:11.050. see the src rules if you don't know what the start and end times for worlds are)
Currently the TAS has saved 6.717 seconds over the WR up to world 4, and the current WR is 58:55, so I think the final TAS time might be somewhere between 58:20 and 58:40, much faster than WR and all previous TASes. (especially seeing as fastest TAS off-site is 1:00:09 and fastest TAS on-site is 1:03:26)
The main improvements are faster routes, using Zoda's current WR route for all of the non-boss-levels, and tons upon tons of pausing during animations to slow down moving enemies (and Druidle's cycle-based fire in 10-10, and scrolling fire, which is only helpful in 13-5, a level not in any%), as Dana's animation finishes while you're paused, but the enemies (and other cycle-based things) pause immediately, so if you pause for the max amount of time during every* animation, the cycles go much slower and you get to a much earlier cycle.
(*It's not EVERY animation as you should still stay unpaused for a few so the cycles fully line up, better to be unpaused during an animation and hit the enemy right as you get to it than be paused during the animation and wait doing nothing until the enemy gets into the right spot)
Will hopefully finish the TAS in 5-8 days assuming I spend most of my time on it for the next few days.