I have always gone the trust route.
With changes to the process, does it make sense to continue to go the trust route vs. individual?

What were your reasons for going the trust route in the first place, and why did they change under the new rules?

Trust route allows others in your trust to use your stuff.  If it's just you, do individual.

From the sound of it, you already have NFA items in a trust. I can't think of any reason to deviate away from that and submit as an individual.

I've used the trust route to avoid engraving my name (lots of characters) on the receiver.  This could be a good reason if you have a long name to engrave or just want to be more discrete...

I went the trust originally because local law enforcement would not sign paperwork.
No longer need signature.

Is it easier to pass the guns to heirs with trust or is it the same no matter which route?

If the heirs are on the trust, then no ATF paperwork is required when you croak.

If not, then really no difference between the trust and if the NFA item is to an individual.

Since you already have things with a trust, it would be easier to keep everything on the trust for will purposes.

But if your trust has other people on it now, then they'll have to have prints and photos included as part of the NFA form.

So - if only you on the trust now, I'd put additional NFA items on the trust.