Bimetallic UK Pound Coin Edge Varieties

Has anyone noticed the edge varieties on some UK bimetallic pound coins? On all these coins the edge consists of alternate plain and milled segments, and normally these are always in the same location, but on some coins the segments are in a different position in relation to the design.

There is a known variety on the 2016 bimetallic pound, the first year of issue. If you hold the coin reverse-side-up, most Elizabeth II bimetallic pounds have a plain segment of edge immediately under the 'N' of pound:

However, about 1 in 20 2016-dated pound coins have a milled edge segment immediately under the 'N'. I have heard that some 2017 and 2018 coins also show this variety, but I have never actually seen one.

Recently I discovered a variety on the 2025 Charles III pound coin. If you look at the reverse and follow the vertical line to the left of the bees down to the bottom, the line ends opposite a milled segment on some coins and a plain segment on others. I've only had a handful of 2025 pound coins so far, and about half are one type and half the other. I haven't spotted this variety on 2023 £1 coins. The 2024 is NIFC and I haven't seen any 2026 coins yet.