I don't find my boar brushes load any faster than my badgers. I readily admit none of my brushes are like scrub brushes, but I suspect it's possible you might be laboring under a misconception. It's not difficult to load soap from a puck with any brush and it can't possibly damage any brush unless your plan is to mash the brush down to the handle on the puck.I was converted to shaving cream ages ago. The soap tablets were presents, but I am not going to use badger brushes where lots of scrubbing is involved. Soap, of course, is far more economical!
If your goal is to make mountains of lather to use the pucks quickly try putting a generous amount of warm water on the puck for a while before you load. Then leave a little more water than usual in your badger and load away. In less than a minute you'll have enough lather for your shave and a couple of neighbors - although that's an awkward invite that I would probably not extend.
Here's the crux of the problem as I see it: you can only use so much lather for a shave and the rest is going down the drain (use plenty of water). You'll have the exact same results (number of shaves) if you just use the first half of the puck normally and then throw the rest away. In any case, no scrubbing please.
For what it's worth, it might be easier (and better all around) to offer them as a nice pif.