Unoffical Systemless Xposed is Now Available — OTAs and Pay Unaffected!
This means that you can install Xposed modules on a rooted device running the stock ROM and continue to receive OTAs. Some users have even reported that Android Pay works using this method, including the OP, however as always your milage may vary.
“The way I achieved Android Pay on systemless is the mount script in the ramdisk will detect the disable file created by Xposed installer. If the file exist, it won’t mount the app_process, but the rest of the ART libs and binaries are still mounted, so ART cache will not re-build when disabled.”
Systemless Xposed builds exist for Arm, Arm64 and x86 devices but, systemless root is currently only available on Marshmallow and above, so if you are running your stock ROM and Xposed but miss receiving your updates OTA then head over to the thread now and give it a try. Make sure to read the thread carefully and make backups!