The difference with reversal 1st stage developing vs negative developing, is reversal requires much greater density build up. The more you have, the less solvent you need. The solvent is usually counter productive on quality when compared to a comparably developed image without.

I have just mixed up a concoction, based on D23 with the following ingredients added in order

dist water 700ml
pinch of Sodium Sulphite - assist the dissolving of Metol
Metol 7.5g - strait from d23 recipe
Sodium Sulphite 50g - d23 amount halfed. I am not looking for lower grain, as this grain that is developed get's removed. It does not really effect the final image
Potassium Bromide 5g - I have seen these higher amounts in other reversal formulas, and I have had problems with some films fogging too much
Borax 5 g - this is a shot in the dark, but likely needs more.
lye 10g - tested to give a ph of 12
dist water to make 1l

A quick dunk of a room exposed leader develops to pitch black in 30 seconds, noticeably in 5 seconds. (orwo n74+)

With this level of activity, I'm guessing I'm probably off on the level of buffer I need.