Bought my Wife a BLU Win HD - X150Q ($50 amazing deal). Got her from 8.1 to 10 using the Upgrade Advisor, I think that took her to .107
I then got her enabled on the release preview ring with the insider app, but there were no updates. - Odd
I left the insider program and the .420 (i think, or close) became available. Installed
Re-enabled Release preview for a while, didn't see any other updates for a couple months.
When I heard 14393.5 was out I moved her to the fast ring and it DID download and update, which was about a month or so ago.
Since then tried moving RP, Slow and Fast rings. Still at .5, never saw .10 or .67.
It does feel like Microsoft only enables certain builds for the Win BLU phones but I would like to know if anyone can confirm this speculation.
Dan