Back to Regas.
If you can't or won't use their wall bracket for siting (I always thought they sounded best mounted this way), I've tried sorbothane boots/feet under each Rega foot to good effect.
Regarding tonearm height, my experiences are old and I have no means of checking for myself, but so many diamonds on cartridges of all prices were set with too much rake angle - several degrees in fact so VTA was fucked right from the start in actual fact! Having the arm down at the back slightly never did fidelity any harm apart from dull sounding cartridges which can't be saved whatever you do, so Roy Gandy did have a provable point all along in my opinion. Their own MM cartridges are slim and get the tonearm level when fitted to a stock Rega.
I'll probably be ignored and obviously don't sell this stuff any more, but I seriously don't think 2mm down at the back is going to be a be-all-and-end-all for any cartridge. The VTA can be adjusted by 1/10g either way on the downforce in any case although I accept some cartridges are so low in compliance it wouldn't make any real difference - and nobody in the right mind is going to use a Decca or SPU in a Rega Planar, are they - eek?
Some cartridges we used that sounded fine with stock tonearm height from memory - Rega R100/A&R C-E-P77/Sumiko Pearl/Supex SM100E, which are all related I believe, Goldring 900 series and especially the 10** models, all of them sounding great in a Rega - I suspect the 1012GX related Linn Adikt would too, Ortofon OM, 500's and 2M models, a 2M Bronze sounding really good in a current Rega 3 and also some of their MC's like MC10 Super and 20 Super, Denon 110 and 160 and also 304, Linn K9 and K18 at the time, Dynavector 10X IV and V, although these are little 'better' than a DL110 if at all but cost more than double now.
Tear down these walls; Cut the ties that held me
Crying out at the top of my voice; Tell me now if you can hear me