I upgraded my TS-653D with these from amazon

https://www.amazon.com/gp/product/B07TP6XXLF/ref=ppx_yo_dt_b_asin_title_o05_s00?ie=UTF8&psc=1

I own the 653D and it has an unsupported max memory of 32GB. I am running 16 (8x2) and I am perfectly happy with its performance. If you want to keep it I would suggest a single 16GB stick and limit your VM usage. One VM would be fine but I would suggest you consider Linux as it has lower overhead. The CPU, while strong enough for most things, feels lethargic very quickly with a resource hungry VM running. I use it for general storage and for my Plex media storage.

This is the RAM I bought: https://www.amazon.com/gp/product/B07TP6XXLF/ref=ppx_yo_dt_b_asin_title_o02_s01?ie=UTF8&psc=1