ModLayer compatibility with multiple modifiers?

I’ve long been using a ‘navigation’ layer with the arrow keys, Home, End, PgUp, PgDn etc., and just as long I’ve been using it with further layers that were the exact same layer of keys but with combinations of modifiers, so Shift + Home and so on. I always thought it was a bit daft to use a whole other layer for a modifier combination + layer, but my multiple layers worked well enough so thought nothing more of it.

So I was pleased to see that since then this ModLayer functionality has been added. The only problem I’ve found in making use of it though is that combinations of modifiers don’t apparently work.

So, ML(LeftShift, 1) functions as expected, but not ML(CtrlShift, 1), say, assuming #define Key_CtrlShift LSHIFT(Key_LeftControl), of course.

I ought to add that these keys are defined as Qukeys.

Anyway, is there a way around this for me?