There seems to be an overarching misconception throughout this thread. Guys, why are you all so certain that the power of the chips has any significant impact on the quality of the modelling? I don't think there is any reason to believe that at all. AFAIK in modern modellers chips mostly determine quantity of things you can run at once, not quality. Look at Helix Native: it can run even on really old PCs despite the fact that PCs run general-purpose processors that are dramatically less efficient at audio processing than dedicated DSPs. And the sound is exactly the same as on Helix Floor. The advantage of having dedicated DSPs in Helix hardware is at having consistent latency and reliability, not sound quality.
I am almost certain that Helix modelling would run on PODHD hardware just fine. Meaning that Helix hardware was not introduced because they needed it for the new modelling, but because they needed a way to sell the new software. Line6 is a digital audio company. Their product is ultimately digital, their hardware is mostly just packaging. If they wanted to just keep updating PODHD with paid model packs, they could. Probably wouldn't be able to make much money that way though, hence came Helix Floor.
At the same time, while I think Helix amps are good enough to be usable all the way to pro level, I don't think the modelling is perfect. There is definitely room for improvement, for some kind of Helix HD amps. They could sell them as paid updates for the Helix, but I doubt that would happen. If that were the path we would probably know about it by now. The fact that they keep shipping new amps with free updates tells me that they are not planning on refocusing their business model towards direct software sales (that would be a very big change). This means a new generation of Helix hardware can't be too far. Given the history of their previous products, it is likely to be very close indeed. Who knows, maybe they even have it ready and are waiting for this pandemic to be over. So with all that, I find it very hard to recommend buying Helix hardware right now, especially the most expensive models.