For any problem first thing is to FLY i.e. keep control of the aircraft. What I suggested is no different than any takeoff except TOGA part. So just doing it by pitch rather than FD how will it create problems is not understood. Normally the PF will announce the problem shift the reference to ISIS and then check with PM if his side is OK then hand over. But UAS doesn't have standard format it comes in many forms. That's why any speed problem is UAS unless it is not. If you hand over to PM and his side is also affected and his speed is increasing he will intuitively raise the pitch and get in trouble. In simulator such situation pilots have stalled the aircraft. As a principle handing over should only happen after confirmation that his side is Ok. Another failure is IR disagree. You get CHECK ATT flag which is in faded pink that is hardly noticeable. The PF side may be OK and PM side may be faulty. If you hand over without checking he could cause an upset and may invert the aircraft. PF looses his speed at or after rotation he just flies the pitch(at takeoff it's value is known), announces, tells PM to check with ISIS. If OK hands over and uses transfer to recover his own speed. CRM, crew coordination everything covered. It can't get any simpler.