If RHR is a concern, switch to Eloralintide, no tirz (Zepbound). Or combine elora with reta, but have to do very little to start. Elora indirectly lowers RHR.
Another thing that works for me is stage 2 cardio or just walking a lot. My RHR is about the same or a bit lower than without reta, but it could be that I'm much leaner now too. But the stage 2 cardio does work imho. And of coarse sleep 8 hours a night, eat less sugary/starchy carbs (not that you do, but when I do, my RHR is higher).
Also, what dose are you on?