Much good input.
I shoot a 47# SAS LB and had to go UP in spine from .400 to .340.
That's with 100 gr brass insert and 200 gr. heads.
Each bow/bowyer at a given pound draw, will have different performance characteristics...everyone has their favorite. I know I do...
I have 100, 125, 145, 175, 200, 225, 250 and 300 gr. screw in field points. Once I have the arrows dialed in with FP, I then put on equal weight BH. I cut from the rear and move fletch 1/4" forward to allow for small cuts... to do final BH tuning.
Many sponsors here would have varied weight FP and perhaps if you bought a wide range, they'd provide you with 1/2 dozen of each?
Good luck! No short cuts! Live fiber materials in stick bows and highly varied lay ups and designs from different bowyers = same draw weight but different performance.
Tune to your bow, then worry about BH's.
PS: Just for me, I found that BH of same weight s hot slightly weaker then same weight FP. I speculate (no way to prove) that the BH has the weight spread out on a longer plane then a compact, fat FP... Elongating the shaft overall thus making it appear weaker... FWIW