This is starting to make even less sense though. If a pole represents 2-5 % of the material of a full block, it should also have 2-5 % of the resources to craft, and 2-5 % of the HP. Likewise if a plate is 10 % of the full block, it should have 10 % of the HP.
But if this just applies to when you upgrade and repair, the whole purpose of pre-made (non wood) blocks falters, as it suddenly represents a much steeper material cost, which really makes the block helper system weird. Not to mention we can't see the HP until after we place, and then damage the block.
Beyond that, if plates move back to 100 %, and bars are staying in 100 %, then why are poles and likewise smaller shapes penalized? Then you have basically "Any shape that is 10-100 % of the block space, has 100 % hp, but anything that has 1-9 % of the block space (ie, poles) suddenly have 25 % ... all it means is people won't build using the very tiny blocks for any structural purposes, which they likely don't do today anyhow. So why change it?
The only reason I see this would be to discourage using smaller shapes in bases ... but why? If official POI's are an issue, talk to the POI creators. Otherwise it really seems to ONLY be to start restricting players in their builds, which is a super peculiar direction for a sandbox game. Let players build what they want, it hurts no one, not themselves, and no other players either.
Now as to bars being intentionally excluded because they are primary window/elevated defenses, that makes little sense too. A pole raised base would suffer from collapses, but a bar-raised base (ie, bars as pillars) would work great. Full HP AND immune to cop vomit as it passes through.
In either case, I just think it's a super peculiar design choice. People were super excited with using 1365 (or whatevver) blockshapes, and suddenly this is thrown in which I can't see having any positive effect for players at all, it's all downside.
But it's great to see this in an experimental version, so that it can be discussed, fine tuned, and hopefully reverted an removed entirely