I’m very happy with the continual progress towards the Crimson release. Again a very informational blog. Thanks to all who made this possible, developers, operators, management, support, marketing, and of course customers and people with a PureOS subscription!
This looks good
If I flash the alpha, will I end up needing to flash the final version later, or could I just update within the OS all the way to the final version?
The update from old comes later, so yes, you’d need to re-flash. You may want to wait for that. However, if you really want to test stuff, you could take a disc image as a backup before you flash the alpha and then revert to the old one by flashing the disc image. That way you can test alpha and any other setup and still get to your original OS setup, just as it was. The procedure can be found from previous threads (basically you make a normal jumpdrive connection, which shows the L5 as external drives to a linux OS and then use for instance Discs app to create full disc image - you’ll need 32Gb of free space for the file - and do almost the same when re-writing that image back to L5).
Even when the update rolls around eventually, I’d still suggest making a disc image backup - just in case you ever need a known good setup to return to, if anything ever goes wrong. This kind of backup is different from making file backups (those are useful too) as it will keep every setting and file in the same state as it was in all partitions (you could take partition images in stead of whole disc, but having them separate mostly just adds more steps both ways). Doing this kind of backups that lets you test and quickly return to any disc image is not something regular phones have. And if you’re using LUKS, your files on the image stay private.
Nice development! Is there a current thread where people are reporting their experiences with the Crimson Alpha release?
Hasn’t been made. The previous ones were made because it was “unofficial” versions, but now, for actual testing, it is better to use the official ticketing system (as requested in the blog text too): As you try it out, review the known issues and let us know about your experience.
In lieu of that, I suppose this thread is as good as any.
I suggest not. 
If anyone wants to discuss issues with the crimson Alpha in this forum, please start a topic for that.