I'm not sure that would help significantly given the accusation at those with feigned head injuries is that they want to disrupt play and break up opposition momentum.Apologies if this point has already been made (I've not read the whole game)
The simple solution to the feigning head injury to get the game stopped is to say anyone with a suspected head injury has to leave the pitch for 5/10 mins for a concussion assessment to be carried out, you can bring on a temp sub in that time, and if the player cannot continue the sub stays on the field and you lose on of the 5 allowed substitutions. Unfortunately the powers that be vetoed that suggestion recently.
Premier League temporary concussion substitute trial rejected at Ifab meeting
The PFA’s head of brain health said the decision was ‘extremely disappointing’ while the FA’s Mark Bullingham said the process would stay ‘under active review’www.theguardian.com
Having to go through a substation for a "head injury" will only disrupt proceedings even further and would be quite easy to workaround by keeping a big stopper back as your "concussion sub" to throw on when needed. In fact Fulham had the ideal man in Shane Duffy to fulfil that role.