Plasma's spare layouts not working on Wayland: workaround

I decided to try Wayland due to some issues I suspect might be related to Xorg. So far, so good. However, it comes with its own problems. Spare layouts don't seem to be working as expected. It's a super useful feature for those who have more than two layouts because it makes cycling through them much easier. According to the documentation:

Spare layouts allow to toggle between small number of layouts easily while keeping more layouts handy close by. For example you might use 3 languages: English, Ukrainian and German but first two are used often and third one just occasionally. In this case you can configure first two as main layouts and German one as spare one - when you toggle with keyboard and left mouse button the switch will happen between main layouts only but you can always choose 3rd layout with context menu.

Here is my configuration:

I want alt+shift to only switch between English and Russian. Unfortunately, this setup doesn't work as intended: all layouts are in the rotation. Therefore, switching from Russian to English takes an extra step through German. Ideally, I want to use German only when I'm practicing it via the applet on the taskbar.

I found a workaround for this bug! Or is it a mismatch? It probably won't help people with more than two main layouts, but it's better than nothing and it solves the problem for me. There is another shortcut, intended to switch to the last used layout!

Naturally, if I switch from English to Russian, this shortcut would switch me back to English as it's the last used layout - and vice versa. Great success!