This was the Atlantic 10 lineup in 1994:

Rutgers
West Virginia
Duquesne
George Washington
UMass
St. Bonaventure
Rhode Island
Temple
St. Joseph's

Only 9 schools. Rutgers and WVU then leave for the Big East.

If they could have added then the following 5 to get to 12.

Virginia Tech
Xavier
East Carolina
Central Florida
Fordham

That would make 4 FBS playing members for a 12 team conference. ECU was playing in the Colonial and UCF in the ASun at the time so both would be getting a basketball upgrade.

Then when Virginia Tech leaves in 2001, add Buffalo instead of Richmond. The A10 would then have 4 FBS teams (Buffalo, Temple, ECU, UCF) for 12 team conference.

2005 is then the year where the FBS football conference is put together. Temple announces its leaving the Big East so is available to start a conference. They invite Marshall and Ohio to the A10 instead of St. Louis and Charlotte. Now there are 6 FBS playing members for a 14 team conference.

They get a waiver as the Big East did and for UMass to transition to FBS and they go with one more Delaware to grow to an 8 FBS/15 BB hybrid.

UMass
Buffalo
Temple
Delaware
Ohio
Marshall
East Carolina
UCF

BB would have Xavier, St. Bonaventure, Duquense, St. Joe's, George Washington, Rhode Island, Fordham to keep down travel costs.

So yes to transform the A10 into an FBS league was possible but needed to start working on it back in the mid 90's instead of doubling down on basketball.

Now I think the only answer is for UMass to align with disaffected CUSA East schools in a new conference and forget the A10 all together which has no potential at this juncture in the game. Marshall, App State and ODU are strong enough to where they could carry their own upstart FBS conference.