Dear HMD Global, Android O has native Support for Substratum theming. I request you not to exclude that theming ability from your version if you're planning to do so. Its been long time Android lovers have been seeking for some sort of theming.
Infact you should clear the grounds for Substratum support in testing if you see any issues in installation of Substratum Engine itself.
Please do this favor to us. We all will be very thankful to you.