Microsoft is pushing out an update to Windows Mobile Insiders on the Release Preview .
The update takes their handset to 10586.242 and appears to only contain bug fixes, which Microsoft will presumably push out to all non-insider Windows 10 Mobile users as part of the monthly update cycle. The current retail build is 10586.218.
Build 10586.242 is of course a Threshold Build when the Fast and Slow Ring are already on the much more exciting Redstone builds, but given the issues Insiders are still experiencing I think a stable and bug-free OS for the rest of the Windows 10 Mobile using population is probably just what the doctor ordered.
If you are an Insider on the Preview Ring, to get the latest update for your phone, just head over to Settings > Update & security > Phone update > Check for updates.