I'll go first...

Is it worth burning an SWU simply to gain access to the FRA First Class terminal on a 4 hour layover?

Notes:
(1) Flying paid biz so It's not really about the seat on this flight
(2) Flight is SFO-FRA-DXB with 4+ hours in FRA

All things equal, I'd rather keep the SWU but the 4 hour layover scares me. Should I keep the SWU and simply waste away in the Senator lounge?