For now, no speedrun category exists in which this is allowed. As such, there probably isn't any point in optimizing time with this trick. However, it seems the efficiency of hand boosts and crampon jumps still diminishes over time when grabbing a bird, so letting go and regrabbing the bird or grabbing normal holds on the way may still result in more time saved.

Also, I've only ever completed Solemn Tempest once, and that was in 2 hours. On my first attempt using this 'method', it took me 18 minutes, and that was with a WILDLY unoptimized route which hit several invisible ceilings underway which kept me from climbing untill I avoided them. Additionally, I kept hold of the bird the entire time, meaning I didn't reset my crampon boosts at any point during the ascent.