I don’t know how to add an algorithm … other than adding a preset made by an algorithm (what you want to avoid).

This may or may not help (not sure) but the H90 has FAVORITE and USER PRESETS parameters (near the top of the preset library page) that narrows preset search results pretty fast.  So, for example, if you have 20 presets flagged as favorites, that’s your short list right there.  Similarly, if you have only created 20 presets, you can select the USER PRESETS parameter and access a short list.

Hope that helps.