xkb.extraLayout not listed in KDE Plasma keyboard layouts

Hi, I’ve been trying to add a custom keyboard layout via services.xserver.xkb.extraLayouts, as per the docs, however I am encountering an issue as the extra layout isn’t listed in plasma’s settings → inputs → keyboard → layouts.

Here’s the complete xkb configuration I’m using : https://pastebin.com/BAVBsKC2

The layout in itself does work, as “setxkbmap optimot” will switch to it properly as well as using “services.xserver.xkb.layout = “optimot”;”
The reason I’m trying to set it in plasma is to be able to switch between this layout and a few others via plasma shortcuts etc.
Note that if I switch my DE to GNOME, it does list it properly and I’m able to select the layout in GNOME’s input settings.

Really not sure what I should be looking at and would appreciate any insight.