With a thumb safety, you could then legitimately bring your XD's trigger pull down to their competition weight and still have a firearm that won't go off with a sneeze.
And again - 8 pound trigger and a thumb safety?
Massad Ayoob has a 1911 that he increased the trigger pull on to be 7 pounds and had an ambidextrous safety. That trigger weight never bothered him nor did it affect his shooting in competition.
8 pound trigger? I have no trouble with the DA trigger on an N-frame, and those list out at 10-12 pounds. And let's not get into a vintage Walther PPK's weight of trigger. I'd bang all day with a DA revolver, so your 8-pound trigger horror stories hold little weight - pardon the pun - with me.
The XD's I've shot have been sweet. Maybe a pound more than a target model 1911 from the same manufacturer - Springfield Armory. Pray tell what trigger weights are you measuring this on?
As for me, I'm more a decock-only DA gun type person.