The MB search seems to ignore strings of 2 or 3 characters when searching (plain indexed search)

example, searching for 'Gaston Lapeyronnie':
'gaston l' finds 'lyle gaston' and louis gaston', but no artists with 'gaston' and a name starting with L
'gaston la' finds artists with 'gaston' and artists with 'la' but no partial match on the 'la'
'gaston lap' same.
'gaston lape' finally works

This seems to be an absolute string limit — similar results searching for 'lap catz': Lap Catz are not at the top (despite being the best match) until you have typed the full name.