i managed to find this in Samsung Open Source Release Center via a personal login. free to obtain, which i am sure other devs have. in case not i decided to at least for now post the link.

according to there terms:

You may print or download materials from the Website for your own personal use or for non-commercial use and you may copy the content for other individuals for their personal information provided that:
• No materials are modified in any way.
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• Our copyright and trademark notices appear in all copies and you acknowledge this Website as the source of the material.
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now that i have done so.
i provide to you the unmodified files that i have obtained and provided the same notice for legal purpose. the information is provided as-is and neither i, nor Android forums or Samsung claim any responsibility from your use of said information and any possible side effects be them positive or negative.

Mods please Feel free to move edit or otherwise if not appropriate.

SPH-L710_VMU MD7 SPH-L710_VMU_JB_Opensource.zip According to Samsungs OSRC

http://download.negalite.com/downloadlist/click.php?id=63

Spoiler

SPH-L710_VMU_JB_Opensource.zip

http://download.negalite.com/downloadlist/click.php?id=64

Spoiler

Notice.html

 

they have source for the jelly been flavor of virgin mobile and others at the link provided just search for are model SPH-L710 you get 8 flavors listed. ill screen shot it https://www.dropbox.com/s/p0u1alt2q0gg9xj/OSRC.png

 

not according to the release center. i can pull the rest if need be and post them asap but i reserve that to be redundant concerding the devs can register for the info just like me. the screen shot provided has all they have at the moment see op for where. how ever if a dev request via pm the file they want then i will pull them and link it to them after pulled and uploaded.

 

and the new upgrade when you want plan 10 bucks a month wait 6 months and upgrade when you want basically. with out contract extensions.

 

here ya go Phone Upgrade Twice a Year | Just Upgrade My Phone | JUMP! | T-Mobile from what i read it is 10 bucks a month which is also the phone insurance. if you trade in a phone broken then the deductible applies. any unpaid balance is waived but you dont get refunded on the old phone.

 

you do turn in your old phone then they way any remainder balance and you start on your new phone. some carriers used to extend you even when you paid out right for the phone it happened to me back in the day under cingular wireless.

 

in keeping with the OP the aformented upgraded
ota for Virgin mobile MG2 Source is posted on the

osrc link i provided in the OP. yes it is VMU flavored.

 

VMU flavored meaning the MG2 is for the VMU edition. Stock (as in right out of the box then applied update without rooting or anything) Touchwiz. if you build it from source it would flash in recovery yes.