F-U-D
Fear, uncertainty, doubt. Hence the term "FUD". Gents, we must use our brains please. As I've proven in my 8 minute, long-winded, really boring and quite repetitive rant, for those wishing maximum cleaning performance (CFM) from their TriStars, feel free to use just the V.A.C. H10 bag. If you don't feel comfortable doing so, then don't.
It is INCORRECT to push false information that you must use multiple filters (bags inside of bags) and most enthusiasts know this. Following a decades old manual that couldn't possibly take into account all things HEPA is being quite ignorant, isn't it? Modern filtration has made massive strides forward, right?
Think about this: Electrolux for decades primarily only used single ply bags as the only filter. Then came multiple ply bags (I've used them both over a 39 year period). The TriStar can easily run on 1 filter only without any motor damage.
If you have H10 pre-motor filtration, adding more filters is essentially pointless and serves to only line the pockets of those selling parts, unless you feel the need to have full HEPA pre-motor and post-motor filters to pass some extreme filtration test.
Also, I don't buy for a minute that most users will somehow jam-pack their bag so full that it somehow requires a crowbar to remove it. Not on Vacuumland anyway.
Last note, everybody should be aware that adding filters reduces motor life by increasing the heat generated by the motor in addition to decreasing CFM. It's a lose-lose situation if you care about longevity. The cooler everything runs, the longer it lasts.
Bill