i can’t see any benefit to not having them there
When I had mine I struggled to get the bum strap the right length to be comfortable. Eventually realised this is because I was measuring it in slightly different places every time. Eventually clocked that if you position these little bits of webbing over your sit bones and then set the length of the bum strap, it increases comfort massively.
Before this I was finding it was either too loose to do anything or too tight when crawling that the harness was putting too much pressure on my hips