Most ARes units already run about one training weekend a month covering IBTS, Ceremonial activities or CT. That's about 8 weekends from September to May.
BMQs and many other IT courses (Dvr Whl, Comms, etc) run on weekends through the training year. Typically this is about two weekends a month for the duration of the course (ie 11 weekends for a BMQ, alternating weekends for about six months). These courses draw on the available pool of MCpl-WO pers as instructors, and Pte-Cpl as students. Ideally, you would have a pool of instructors who are not required to participate in other unit training activities, but that is unrealistic as very few ARes units can spare the junior leaders. For the most part, BMQ instructors are also Section Commanders within the unit's normal organization.
Note that IT does not count towards the 30-ish days per year.
Parade nights are inefficient, but the second order effects of changing that system have to be considered. Taking away parade nights in favour of additional training weekends means that most pers will be asked to work at least two weekends per month, and others (generally at the leadership ranks) even more.