Which tonearms just sit over the plinth surface?

Sorry,I have no experience with the Temaad.

RS-A1 is not for the faint of heart. But once you learn its eccentricities, I don't or I no longer think of it as dangerous to cartridges. I've never damaged a cartridge in the RS-A1 (knock wood). The DV505 is of course an ordinary tonearm which you can set down anywhere but of course one must be careful not to nudge it once you've aligned it. I would suggest taping down the flat base element. Of course, bolting it to the plinth is easy and best.

How good is the temaad? I had seen the rs but scared but possible instability and playing records would see like a thriller movie. Is the temaad same league that top arms or just mid class?Really have no idea. Thanxs

I have an RS Labs RS-A1. It's great for moving a tonearm and cartridge rapidly from one tt to another. The only other well established tonearm with which you can do this, that I know of, is the Dynavector DV505. Its base is a fairly substantial rectangular piece of flat aluminum that can support the whole structure without any danger of tippiness. (I've got one of those as well.)

Temaad Audio Warlock is another free standing tonearm.