This is the first I've heard of the H13. WOW!
So, the original question was about A through F. As awesome as the H13 appears to be, it weighs 203 grams. Continuing with Big Bertha as an example (and yes, I know, it's just one example and not necessarily the best one) the estimated weight for the model is 71 grams, and an Estes C6 weighs 24 grams, so the H13 by itself outweighs the BB/C6 combination by about 2.1:1.
It'd be one thing to put a 29 mm mount into a stronger BT-60 size tube and fly everything from A to F. It'd be another again to shove a 203 gram motor in the back and keep the rocket stable.
Maybe a taller rocket would help. Super rocs have their own problems, of course, but maybe double the length of BB. Then one would need only something in the ballpark of half the nose weight to balance out the motor weight. That doesn't fix the issue of weathercocking on the A engine, but it may make some things easier.
OK, now to get off my nose weight soap box and onto the Aspire band wagon. That one doesn't weigh a whole lot; it's advertised to fly well on the low thrust F10. So how does it do on an A8? If the A8 actually had 8 N average thrust and peak thrust to match then it'd probably do OK (unless it needs too much tail weight to keep from weathercocking) but unfortunately the designation is a lie; the thing only has 4 N average thrust and the peak is less than 10.
The desired target of A through F may be harder than B though H, and is certainly harder than C through H, specifically C5 through H13. But the goal is the goal, and harder is more fun (in this situation).
(The B6 has more average thrust and peak thrust than the A8. And the 13 mm A10 has even lower average thrust yet. These designations have a defined meaning, and I'm sorry but the "A8" is really an A4. The "B6" is really a baby C5, but at least that's close. The "C6" is really a C5, and the "C5" is really a C4. Since the "B6" and "C6" are correctly two different C5s, I guess calling the baby C a B5 isn't such a crime. Really, all of them are somewhat close to correct except the A engines. But I digress. Frequently.)
