I think you can consider Tencel suitable for anything that would otherwise be woven in silk, for sure. And for many things that would otherwise be woven in cotton. (It’s not good for towels or items requiring absorption or for table linens that require more stiffness.)
You can substitute 8/2 Tencel for 8/2 cotton, 10/2 Tencel for 10/2 cotton, pretty much straight across. Silk substitutions are a little trickier since the relative thickness of silk yarns is not as consistent as for cotton. But this should get you started!
Thanks for writing and I’m so glad you liked those scarves!