
not sure if you actually want form advice but you got some rounding of the back (normal with 1RM) but i think you can reduce the amount by “pulling out the slack” before you begin the ascent. this causes your arms and shoulders to be pulled out maximally and then you push through your feet and start the actual deadlift. your butt goes up before your shoulders do which causes shear load on your spine and that rounding i was talking about. sorry for the paragraph but i used to do the same