Sorry for the double post, but I tested some methods by recording PC BBCT@60FPS and comparing with the frame data and concluded some things:
-You can discover active frames only through whiffing and by counting the nº of repeating frames. On hit/block is very difficult to figure out due to hitstop. This may prove to be troublesome for auto-combo moves (5AA 5AAA).
However, it may possible to if you know their respective attack levels and hitstop.
-Same thing applies to untechable, you'll need Hitstun to discover it.
i.e: Right after Ragna's 6A hit, I counted 39 frames before the tech. 6A is a level 3 move which has 13f hitstop. I then subtracted 39f and 13f... and voilá, 26f is the untechable, which is exactly the value on the table.
So yeah, building a attack level table from scratch may prove hard.