I think Bardsey may be a worthy candidate for use as a semi-dwarf apple stock. It has several strengths that factor into this thought:
produces juicy fruit in drought conditions; scab, FB & mildew resistant (can’t speak to CAR, since that doesn’t occur here), natural semi-dwarf, begins limited bloom early in life.
Eliza Greenman alerted us to the influence of rootstock to budwood over the decades, so juiciness would be a plus.
Bardsey is one of two fully fruiting apples in my care, but is irresistible to codling moths & squirrels. I like its lemon overtone - making the best slow-baked whole apples so far, excellent sauce & pies. It might be excellent as a cider base. Its fruit size & PSF bloom are also points in its favor.
Against keeping it as a fruiting tree: stringent thinning must be done or the negligible stems will cause swelling fruit to push each other off; nearly impossible to cover fruit early enough to ward off codling moth worms; erratic bloom time & harvest (from earliest bloom to late mid-season, harvest anywhere from August 25 to September 30).
At this time I will try planting a dozen dormant stems before winter & covering well with mulch in hope some will take root. Next spring I plan to top work all but a nurse branch.