In the interest of improving back and arm jackitude would it be appropriate to do controlled efforts and rotating exercises via GPP work at the end of a session e.g. DB Row AMRAP for Sub maximal sets in 7-8 minutes along with Myo Rep arm work at the end of session?
Are you asking if doing more back work that induces muscle fatigue via large amount of motor unit recruitment is likely to increase the size of the musculature being trained? Yes- it should.
Are myoreps or an AMRAP enough for this? Potentially.