2175 is pretty damn high for the memory clock 24/7. Remember, these memory chips were designed to run at 16Ghz (2000 clock), the ones that made the cut went into the 16ghz GPU's (like the Rx 580 8Gb, the Rx 590 ) and the ones that didnt were slapped onto boffins at 14Ghz ( 1750 clock) and even lower end 12Ghz (1500 clock). While you CAN oc them to speeds over 2000, its generally recommended to keep the speeds as low as possible and achieving higher hashrate with tighter timings ( better straps ) - keeps the chips from burning out. You NEED to undervolt the memory for 24/7 use and not use it at stock volts. So a 1500 strap running at say 1925 is preferable to a 1625 strap running at 2125 for a similar hashrate.
Well I haven't run into any real problems. What you have to keep in mind is that memory doesn't run at a specific clock like a cpu. The base clock is rather a poll rate and the memory can either keep up or not. Imo it's better to run it at a higher clock but looser timings. The 1625 strap is very tight and unstable.
The recommendation is to rather increase the memory speed and decrease the gpu speed and voltage as that is where most of the heat is generated. Ethereum is in any case so light on power usage that it doesn't really matter. Keep in mind the stock clock is 1750 so there's still plenty of room for stability one day when retiring them.