I would be looking towards the 2024 elections when I'm pretty sure there is a really good chance the Stupid Traitorous Republicans will have set the stage for a complete Communist take over (thinking they will get a part of the action), and they are going to go for the whole lot in one big go.
possibly with registration followed shortly by confiscation, possibly just straight making stuff illegal.
They are probably also going to tighten up parts hugely as well.
I'm not sure having a bunch of lowers will put you in any better case.
Considering that you can buy entire ARs for the $400+ range, I'd suggest that you just stock up on more complete rifles.
Since it's in for a penny, in for a pound, might as well have the whole pound.
Also just for fun, I'd make sure to purchase as many cheap used ARs as possible (where the original owner doesn't know you, like at a gun shop used etc.), because tracking them down is going to be a lot more work.
This is why they are pushing for "universal background checks" Specifically because that is their back door to universal gun registration.