Mesa Nomad 45 question

I seen some of the mods on here for the Nomad. One mod is swapping out a cap for the effects loop to brighten the amp. Does this only brighten the Fx loop or does it work on the amp overall? I never use my loop. I dont want to do a mod for nothing. I seen a picture of this mod done. It was on a Nomad 100. Is the cap in the exact same place? Im not good a reading schematics but Im very handy with a solder iron.

Also does anyone know what makes this amp so heavy? Would a speaker swap lighten the amp? This is my first post on this forum. Thanks in advance for your time.