What a wind-up!
To qualify for MFF as commander you must be 737 and 757 rated. The only way to get a (T-fly) 757 rating is to win it in a seniority based bidding round. Since the T-fly 737 DECs would not have sufficient seniority to do so, I'd opine that the suggestion a 737 DEC is somehow going to beat a (more senior) mainline effoh to a 757 command via MFF is the singularly most colossal pile of horse manure I have seen fertilzing the pages of pprune in quite some time......