With an Epson 5050 on a 110" screen in a dark room you definitely don't need any gain. A fixed screen of course is the most economical but if not possible TAB Tensioned is desirable but also expensive. 110" from 15' is on the very small size for most of us but it is purely personal preference so what ever floats your boat. Is the ceiling black also? If not it opens up a new can of worms as to go ALR or not.
"Smart enough to know better, to old to care" ------ Dedicated Bat Cave Home Theater, JVC RS49U/Mitsubishi HC7900DW Projector, 110" 16:9 Jamestown screen with variable power masking for CIW 2.50:1 to 16:9, Marantz 7009 with 7.1.4 Atmos with Ohm mains,3 DIY Subs (2 15" (1 ported, 1 sealed and a 12" 4th order bandpass), 1 DIY butt kicker, Custom Built HTPC, 18TB DroboFS NAS