It doesn’t have a formal master sketch tool but there are workflows for master sketches that work well by importing geometry into feature sketches. Mango Jelly Solutions has one on youtube.
But there are no easy and intuitive ways of doing that. Compare it to the Realthunder’s Link Branch version which has `export single geometry` and `export multiple geometries` tools as well as automatic SubShapeBinder generated when edges forming a closed loop which are selected from the sketch before padding.
Though I think the sketcher improvements that have gone into 0.22 (and aren't in RealThunder's work) are absolutely more valuable, and I'd rather see the facilities you mention reimplemented on top of those.
I'm not convinced by the automatic subshape binder bit; I think that is better handled explicitly.
Maybe we will see something that formalises the master sketch workflow, but I don't think it is particularly universal as a design technique. To me it seems it would maybe be better to see some kind of improvement to the selection mechanism for importing geometry from other sketches. I find that a little opaque.
I would like the built-in part design wrapper facility. And I think there are improvements in the cross-section view; I think Persistent Section Cut is often more hassle than it is worth.
As interesting as the RealThunder branch is, it's one guy's fork of experiments, and he didn't have to get agreement from anyone else or follow anyone's coding standards but his own. And for better or worse that fork is now (edit: likely) a dead end, and all the energy (edit: and money) is elsewhere.
Some great stuff has come from that branch but I don't think there's any reason why it should just be automatically blessed.
I don't know if that is impossible but it would be an incredible amount of work for one person to manage. He last merged a year ago, AFAIK.
I'm sure some people will stick with it over 1.0 for a good while.
(ETA: For clarity, I think he basically saved FreeCAD.)