The real solution is to be found by closing the station completely, and connecting it by travellator to Manchester Oxford Road to preserve the exits.
Appreciate I'm straying well into crayon territory, but given how hemmed in Oxford Road is by large expensive real-estate, and how relatively unhemmed-in Deansgate station is (not to mention how handy it is as a Metrolink interchange), is there not a case for actually closing Oxford Rd & expanding & improving Deansgate?
I know Oxford Rd has it's listed wooden roof etc. but as a functional station, it's pretty poor & as noted, in fairly easy walking distance of both Piccadilly & Deansgate.
Obviously any closure would also have to be accompanied by much-improved access & capacity at Piccadilly.