For anyone else using the old PBE one-click samsung straps (aka generaleramon's ubermix 3.2) on RX 4/5XX 8gb GPUs, and seeing subpar ETH h/rs due to the tight timings limiting mem clock frequencies... I've been able to get my samsung 580-8s more in-line w/ the microns (~32.5 MH/s) by loosening a couple settings which then allow raising the mem clock (combined w/ a REF increase i use on all my 580s):

--REF 10 --RC 70 --RFC 157 (from REF 5, RC 65, RFC 136)
mclock 2145-2185 (from 2085-2145)

other relevant bits:

cclock 1175, 806mv, phoenixminer, and ubuntu 18.04 + amdgpu-pro 18.50 (though windows should behave similarly)

You could prob get to ~33+ w/ a 1200-1250+ cclock, while I may have slightly overshot on the loosened timings.  But as usual, I'm more interested in efficiency than max h/rs.
Also, mclock is still a bit limited, as i believe CL (currently 21) would need to be relaxed to get to 2200+ MHz -- which as i understand, can't be done w/ the tool atm.