Lucky for you, my VBA folder was backed up to a second hard drive right before my system32 crapped out. After some trouble on my part, I was able to track down
the test run and post it on microstorage.
Note that the run uses very few savestates, never employs frame advance, and had not much planning involved. Cardboard found that you can still damage bosses when they're in their coffin, which is a tactic I did not use. Aside from that, the 2x battery can probably be skipped and you don't have to care so much about not being seen as much as I bothered to do. A good run would probably beat 2:2x
e: Also note that Bisqwit is allowing the modded version of the ROM for Boktai. It allows us to alter the solar input levels, thereby circumventing the problem of needing an actual solar sensor. My ROM was titled "Boktai - The Sun is in Your Hands (E) (M5) (Cracked).gba", but it should work with a lot of different ROMs that employ the same workaround.