Where to go next with the turntable

you might want to try changing the cartridge 1st, then later the TT, use the new cartridge on the new TT's tonearm.

The best bass I ever had was a combo of the Thorens TD124’s 9lb platter, SME 3009 tonearm (with removable headshell) with Shure’s last V15vxmr cartridge with beryllium cantilever. Wonderful in all respects, until I broke the brittle cantilever. I now have a new stylus: Jico SAS on boron, in that Shure body. Jico has a brush, but it is not damped like Shure's were.

I have found, the stiffer the cantilever, the better for bass. New, I buy boron cantilevers (not the stiffest, but darn good!). Occasionally I buy low-use used, like a Sumiko Talisman S with a sapphire cantilever that sounds terrific.

I also have VAS re-fit a broken cartridge, the latest is simply un-available without re-building: AT33ptg/II MC MONO Body, new boron cantilever, new advanced tip.

And Shure's 97xe with factory damped brush with new boron/ML stylus for the occasional warped LP.

And, of course I could not do any of this with ease if using a fixed arm.

In my experience with Linn, it was very sensitive to the shelf it was placed on. In fact, my dealer who installed it was shocked at the difference in sound between the standard wood shelf on my wall shelf and the Neuance platform, which unfortunately are no longer made. I don’t know about Rega, but you might try some different platform options before changing. Even a simple wood shelf with Vibrapods could bring it closer to what you’re looking for. Or not. 

I have wood headshells, magnesium ones...aluminum ones. Each specifically linked to a cartridge type. You can open up access to many more cartridges with a removable headshell.

The turntable has survived all these years because of constant and relentless improvements. The formidable connection integrity of my 1200G (Technics) headshell to tonearm inspires a lot of confidence.

Give it a try.

@traudio The Link will show a Sound Smith explanation of their High Output Moving Coils and how pf loading can effect them. 

The D.U.C.C Tag wires are unfortunately restricted to Luxman Headshells only. This is unfortunate as this would have been the mist cost effective method to experience the Wire in the signal path.

Learning where to source Forex Foam or the equivalent material in the US, is more than worthwhile an an endeavour, as the cost incurred to experience it and the potential end result is real bang for buck. 

As I have seen you are long term associated with Linn TT's, the Forex Foam improved a Heavily Upgraded Linn in one system, to the point the Mat exchange was seemingly like a new TT was in use.  

 https://www.sound-smith.com/articles/transformer-use-soundsmith-mifixed-coil-designs

I winner why Soundsmith told me it didn’t matter when I asked them directly?