Another convert here!
Finally got around to a "proper" test - with the stock I mixed a month ago. The negs I developed then were inconclusive, as I used a new (to me) film, a new (to me) developer, a new (to me) process - inspection - in my new darkroom. Too many variables...
This time I developed two rolls of Ilford Pan F+ for 9 minutes using 1:1:60 dilution. Beautiful negatives, with full details in both shadows and (extreme) highlights.
A third roll, Kodak Plus-X, also looks promising at 8min; but as I'm not that familiar with this emulsion I can't evaluate it before printing.
BTW, I used 6.3g Sodium Carbonate instead of stock B. Thanks, Sandy, for measuring your solution!