I've tried tons of miner settings as well as voltages and clocks....
I'm having a hard time holding above ~17-18mh average hashrate per card
I haven't messed around with it but I get ~12-13mh/s on x16r on a Vega 56 with WildRig Multi
Are there any other decent x16r miners for AMD?
12-13 MH/s on Vega 56 is pretty much what you'll get. You might be able to squeeze a bit more but at the cost of a lot more power draw. Not worth it. It's quite sad nobody's bothered to really do a proper job on the x16 algos for AMD. Probably due to the fact it's a major pain in the ass to do it!