Bearing in mind that this proposal is driven wholly by politics of envy, I think that a lot of "target" operators (where the operator does genuinely decide where the plane flies next) will escape this proposal.
A lot of corporate jet operators will meet the non EU resident operator requirement.
These are the most emotionally targetted people. They have the biggest N-reg jets. And they will escape all this.
We have been around this block in 2005. Those operators who had fleets big enough to rotate them (through another country, or through a leasing company) so no single airframe spent > 90 days
parked in the UK each year, would have escaped the reg, while the little N-reg people would have been caught up. This would have been completely hopeless in the politics of envy scenario where it is the big shiny stuff you want to target. (Plus you would have needed to keep a "parked hours" logbook, in addition to the usual "flying hours" logbook(s)
).
And the permanent number of "genuine" non-EU visitors flying into the EU in N-reg planes will make detection very hard, because a lot of them will be speaking normal English, etc. There is no "proof of residence" piece of paper you can wave at the ramp inspector. That's not how aviation works.