I process my films in Dixactol Ultra
I too have used his developer and that got me into the habit of using a water stop bath for all my films now. I give two agitation/baths of 30secs each. I am about to try his non-staining two bath dev for Fuji Acros as I understand staining developers might not suit the emulsion characteristics.
Nothing really stopping you using both a stop bath and water. Water isn't really a stop you're just washing the film.
When to Barry's website=
When throught the Ultra instructions-
and it says -
"Stop and fix in the normal way ensuring that the stop bath is not too strongly acid."
So you can use a stopbath as long as it is mixed a little week. Or you could switch to the milder citric acid stopbath.
The whole issue with staining developer is the tendency for acid to etch the stain developed during development.
One other consideration - Ilford and Agfa *both* advised against the use of an acid stop bath for film due to the tendency to cause pinholes. I can remember that clearly, although I haven't seen it mentioned lately. I don't use acid stop baths, *except* between the color developer and bleach-fix in color printing. I've found it necessary there to avoid uneven processing.
I use conventional 28% acetic acid stop bath on both my pyrocat HD and ABC pyro negatives. I do however dilute it to 1/3 strength for the pinholing consideration. I have not noticed that the stain has been markedly diminished, in my experience. I like to have the development stopped in a more abrupt manner then what a plain water stop bath would provide. But that is my method and yours may differ.