I'm absolutely certain, Trixx seems to be the only utility which allows you to do so without any hassle anyway.  A wide variety of algorithms benefit from setting the memory to 150 Mhz [600 Mhz effective] such as Quark & Qubit which rely on latency rather than throughput.  This  sets your memory bus to a strap with tighter timings which will ultimately lower power consumption and heat and also allows for more overclocking headroom.  To prove my point, I managed to yield 23 MH/s for Quark, a similar figure for Qubit and 37 MH/s Ethereum & 620 MH/s for Decred in dual mining mode on a 390x without rejected shares.

Has anyone tried Stilit's bios or any other modded bios for that matter on Ethereum?

Seriously why so complicated, its simple... Install drivers that allow underclock (13.x) then put open cl dll's from the 15.12 drivers in the folder with the miner, the miner will use the 15.12 dll files for opencl and any over/underclocking will be controlled by the installed drivers. No restarting changing settings or generally screwing around, simple and clean.

Edit: dont understand what im talking about read this: http://cryptomining-blog.com/tag/amdocl/
Ps this wont work for newer cards that require newer drivers ie 370,380,380x etc