It would be very tight trying to do it exemped but I think still being perma at 22 would be possible. You'd definitely need all the slots to 50 but you can figure on all the major sources still being there exemped to 22 if you use attuned versions where applicable (5x 10% from purp/ATO, 5x lotg, a 7.5 from basilisk). Call to Arms' 4-piece 6.25 could be hit twice. Depending on your secondary preventive medicine's 8.75 for 6 could be there. If there's any low level recharge help from your secondary like kin or rad it'd be much easier. Also I'd think you'd want offensive amplifier's 15% and sg base buff's 20 active at all times.