I don't know how the SB reacts to out of range arrows, but 400 is already over the edge for being too weak at 100gr. GTs chart has them up to 65lbs with 100gr so I would be real iffy about adding tip weight.
My 28" GT ULs come in at 354gr with 100gr tips. I use 4" Duravanes.
Pin nocks would net a 4.4gr increase. Illuminocks definitely would add some weight, 22gr. I can't find what Turbo nocks weigh (if you shoot a drop away) but I bet they'd add weight.
Wraps would add 5-15gr.
15-43gr puts you at 363-391gr.
Just try messing around with different components if you want more weight.
Since you want this for hunting I would worry more about noise, KE and momentum/penetration than I would about them claiming you voided your warranty over .03gpp. You could turn it down a pound if you were that worried about the .03gpp.
But by shooting the lightest arrow you can you are basically going into the woods armed with the smallest caliber rifle you could find.
As for being kind to the bow, I'm not sure how much that matters. I've had cracked limbs shooting [email protected]
and there's people shooting 5gpp that never had a crack. I'm starting to think it's just how lucky you are when they reached into the bin of limbs.