I’d be more concerned as well if this would be an over-night change, but I’d say that the rollout is slow and gradual enough that giving it more time would just lead to more procrastination instead, rather than finding solutions. Particularly for those following the news, which all sysadmins should, the reduction in certificate lifespan over time has been going on for a while now with a clear goal of automation becoming the only viable path forward.
I’ll also go out on a limb and make a guess that a not insignificant amount of people only think that their “special” case can’t be automated. I wouldn’t even be surprised if many of those could be solved by a bog-standard reverse-proxy setup.
I’ve made similar coasters a while ago, just with a stone tile as the base. Despite having to endure a cup of hot tea every day, it’s holding up very well so far and stays clean.
The PETG did minimally deform after months of using it, which is both good and bad. On one hand it’s now formed in a way that perfectly fits the specific cup I use, but that also means that it’s become a bad fit for every other cup or glass.
Your comment about using TPU has given me the idea however to make the tile reversible with the current PETG on one side and Flex material on the other.