On Friday, August 17, 2018 at 10:54:58 PM UTC-5, Larry Kraus wrote:

Table legs will probably need to retain a
square section at the top, I think it would be simplest to shape the
square-round transition with hand tools.

Or the table's skirts, themselves, if applicable, could be mortised into the round legs, a bit, plus dowels or tenons, then apply a diagonal corner brace. This process may be (probably would be) more work (and troublesome), than retaining a square leg-ends, as Larry suggests, in the first place.

In this or any leg-configuration case, it would be best to cut the mortises, before turning, but I suppose you already know that.

As to that router jig, that seems a pretty neat solution, to a no-lathe "problem".

Sonny