PDM 4 and PDM 3 (build 5626)

1.
Being a beta tester for PDM 4 entitles me to any sort of discount or free upgrade of my license of PDM 3 to PDM 4? Or do I have to pay the standard upgrade cost? Some PDM 3 buyers seem to be entitled to a free upgrade, what are the conditions for this (date of purchase after when?).

2.
My 'Application Update' dock widget tells me about a PDM 3 (build 5626), which is otherwise unannounced at Parallels site, and the download PDM link now goes to PDM 4. I was able to find the link to the download via Version Tracker. What's the status on this update, what does it fix? Is this official? Is it safe to update from 5608 (or 5624)?
And, a thing that puzzles me a little, why is the .dmg file 111MB (5608 and 5624 are both around 88MB)?

 

1. You probably need to contact sales team about this questions, but I did not hear that was promised discounts apart prizes for beta testers
2. 5626 is official but only US version for now, we will put descriptions shortly