It took quite a while to get this, but I kept grinding since I knew it was only a matter of time until I got the record, especially with my new strat. So my start is a bit different than Ico, and this seems to be the fastest strat I could find. The rest is just the same old strats.
I honestly think this is quite optimized now, seeing as there isn't very much ways to get faster other than perfect landings in the slopes to maximize the speed. There is however one strat that I think could prove optimal though, but it is really difficult to pull off. That is to instead of going for the top side wall, you only two jumps into a Charged Dash (a normal dash works too) on the bottom pillar. It's very hard to get enough height, let alone the jump at all from it, but if done right, you might be able to push down the time way lower!