Seems like it has not gotten any updates yet, hwmt.ru doesn't have it. So I'd wait with rooting... I guess you could unlock bootloader, flash twrp and backup everything but /data. And leave it encrypted. Since no update exists you won't get hw_data and public_data for your model, and that causes problems with a bunch of apps if you don't flash them after decrypting.
And even then, if something goes wrong that can't be fixed with backup you'd have to use a paid service to update... But since no update exist you'd have to rebrand to a different model. (which probably isn't a bad idea if you're still on B136

). I'd wait or rebrand anyway.