Only current user known is plasma-desktop, from R119:737b114c2fa5bf0b01951eeb2eef22ce7fcdcfa1 No other hits seen on internet

No idea what is the most simple approach here, given KF releases are branchless, and Plasma has branches, and there are rolling distributions and non-rolling distributions, thus combining old KF and new Plasma, as well as new KF and new Plasma.

Perhaps install backward-compat version, and drop once Plasma 5.16 is no longer released due to Plasma 5.17 ?

Something to consider in time for Plasma 5.18, post 5.17.5 and before 5.17.90)

Maybe you can install one with the typo and one without, so Plasma and whatever else can be ported and start doing things properly.

Np other opinion? Would then go with this in the next days...