this is an interesting request; i know it's been touched on in the past but you've explained it quite well.
i guess the first answer is that you can't currently do exactly this in farr, though you can get pretty close by using FARR aliases. it might pay to tweak the aliases a bit to make it almost exactly what you are asking for, but let me explain how you would do it first in farr.
in farr, you would do this using ALIASES (not search score patterns).
as an example you say:
in QS you can right-click an item in the results list and choose 'make this default for <current search text>'.
in farr, you would right click, and say "add this to alias group" -> New group.
then you would use the search text you want as the alias group name.
just creating this alias will normally do everything you want, give it a higher score as long as what you are typing matches an alias -- and the closer to the alias name the higher the score.
it would be fairly easy to automatically keep a list of [search terms , item launched] pairs, and boost those scores in the future, and let users manually tweak those pairs, which i think would do what you are asking -- i suppose it's easy enough to do that it's worth doing. i guess this could even be added to the launch history and just give a generic bonus to previously launched files, and then an extra boost if the search term exactly meets what you searched for before.
on the other hand, i guess you could say the current farr philosophy would be that if you use the same search to find a file over and over again, you might consider creating an explicit alias for it using the method i described above -- so in your case you would create 2 aliases, one fro "dr" and one for "drop".