Focusrite Scarlett WDM port mapping

I record through two sound devices, Focusrite Scarlett 18i8 (1st gen) mostly for mics and a Yamaha THR10 for bass and electric guitars, and don’t like having to change device in Cubase as it loses certain connection mappings each time (eg. External effects loop in Cubase 9.0). So dunno if this is a good idea but I’ve finally figured out how to use them simultaneously via ASIO4ALL. Haven’t fully tested this yet but right now the problem is that only the first eight inputs on the 18i8 are shown but I need to include a couple of ADAT ports that aren’t showing (11&12 probably). I found an old post elsewhere about the same issue on different hardware suggesting the device only made eight ports available to WDM and so that’s all ASIO4ALL can map to ASIO. Sounded plausible.

So the question is, is it possible to map which ports the Scarlett makes available to WDM and if so, how?