Of course, since nothing they do comes without a trade-off, they will be making the trust route somewhat more painful (requiring fingerprints and background checks).
However, if an armed citizenry is supposed to keep the government in check, why not HEAT warhead anti-armor weapons? E.g. in the context of this discussion: https://news.ycombinator.com/item?id=6186569 which touches on the widespread police procurement of light armor.
In those states, so long as the NFA branch issues the stamp and you are (federally) legally allowed to possess the item under the NFA, it doesn't matter whether you or a trust owns it.
Of course, the trust must be valid under the trust law of the state you reside in or else it cannot legally own the items, but competent trust attorneys are not too hard to find.
It also fits with the published data showing that police officers commit violent crimes at a significantly higher rate than non-LEO concealed weapons permit holders.