Yes the 28 days’ time lime works after S56 request.
I received my grant yesterday and my time line is below.
Visa – 186DE
Visa and nomination applied – 06th Sep 19
Nomination approved – 10th Sep 19
S56 requested medical & partner English – 14th Sep 19
Documents submitted on 24th Sep 19.
Visa Granted on 14th October 19.
All the best for those waiting for the Grant and thanks to this forum.