You say "for every unicode symbol", which I guess is true if you search by code, but for anything that isn't in your curated set I'm unable to even find it if I paste the literal character or use the "official" name.
eg ℝ "Double-Struck Capital R" won't show up at all unless I search it as U+211D.
eg ℝ "Double-Struck Capital R" won't show up at all unless I search it as U+211D.