The 2024 monk is very strong indeed; I think your tweak won't change much, though. The patient defence upgrade isn't until level 10, which most campaigns don't reach, and even then the PD upgrade is worth, at that level, 11 temp HP on average whereas your buff to the HP die adds 10 permanent HP so...kind of a wash. A mild buff to defence at lower levels and mild nerf at higher levels, I guess, though I imagine level 10+ monks will be doing flurry of blows for three extra attacks most of the time.
My current monk is level 7, and with tough as the starting feat and 14 con they are sitting at 66 HP, with deflect attack basically negating one hit per turn, a solid AC (18, thanks to a ring of protection), evasion, patient defence, and hand of healing...they're pretty durable, with high offence and stupidly good mobility. I do think they are a bit much.