This is mainly guess work on my part, but should Win10 on Arm see the light of day for phones…… Would you try a back door way in with you 950/950 XL/Alcatel Idol 4S/Acer Jade Primo, or newer as yet unseen device? I ask as I have the feeling someone may find a way to break it open on other devices much like some have Continuum running on lesser devices….. The core will be there already, so will you try should a hack pop up?? Which phones will have the best chance of being able to handle it?
None, unless specific drivers are created for all the hardware, I cant imagine it happening but like you say, someone might find a way, I think it will be a dead end like trying to run android on a windows phone.