so nokia (or rather, hmd but for the sake of it, let's call it "nokia" ;p) decided to go with "pure android". i don't like that idea since stock android is the most incomplete version of android available and what it has works worse than on the phones google copied the features from (just look at the terrible split screen option on stock android versus the original version on samsung phones).
anyway, one of the advantages of non-"pure android" is the ability to let users customise their phone to their liking. customising is more than adding a new wallpaper though. it's being able to change, for example, the colour of the notification tray from the horrible colours google picks to a colour we like. it's the ability to change the background of the system settings for example, from white to black.
all that can be achieved with themes which, until now, oems had to provide the framework for. most of them did (sony, samsung, lg etc).
fortunately for nokia, sony has donated to the aosp their runtime resource overlay (rro) which google incorporated in android 6.0. this was the base for many of the theme engines other oems created. but sony continued to work on that project and it eventually turned into overlay manager service (oms). this was done by sony as an open source themeing engine and google has now completed the incorporation of the oms into android 8.0 oreo.
what does that mean? it means that android 8.0 now has a fully fledged theme engine built into the os. the only thing that exists now between that theme engine and the ability for users of stock android 8.0 to use those themes is a "theme portal", an app that makes the connection between themes that can, for example, be downloaded from the google play store (and there are many already there made for sony's and lg's phones as well as for substratum) and the phone.
so what i would like to see nokia create is simply that app.
it will still be "pure android" and therefore its existence will not delay or complicate the process of approval and deployment of updates. at the same time, nokia users will be able to have that app that makes the connection between the theme engine google built into the os and the play store.
nokia can also even create some themes of their own to use as marketing for example. you can have a theme designed around the original 3310 for example. or nokia health. or whatever comes to mind.
i therefore urge your software engineers to look at the android 8.0 code and create that app to be deployed for users of nokia phones running android 8.0 and above. it will allow us to make our phones our own without compromising your insistence on "pure android" ;)