If you want to remove bottom laminations ---- can't you add a rectangular bar to the bottom of the beam attach it with SDS screws very frequently. then calc it using a transformed section thingey like in the PE exam reference book. Or bolt steel rectangular bar to the sides of the beam thru bolt the beam and ignor the wood - only use it to stabilize the side plates( say 1/4" thick x 12" plate x 21 feet long. or the eaisrer may be to add GLB next to the original or replace the original. this may get very expensive for not much gain. why not furr the entire ceiling down to the bottom of the beam.
something different
Tim Rudolph
Pinyon Engineering