@eddy_frazer -I understand your concern but its the better way of doing it.
Coz if you are planning to do it viaUpgrade groups with package..it wont work and it might even create a new issue altogether...however if you are exporting a package and deploying it ..It should be fine
So what i would suggest is upgrade SEPM to Mr4 then MR4MP2.
Export a client install package for Mr4Mp2 on few clients for testing if everything goes well then start deployment for the rest.As SEP is very environmental product so it might work in my Env. but it might fail in yours so its always advised to test it..if you are doing anything not recommended.
@FinlandRobert --
Can the MR3 clients be upgraded to MR4mp2 directly?
By pushing package yes..But by Upgrade groups with package-NO
WIll the MR4mp2 console support the MR3 clients?
Yes ..it is backward compatible.SEPM Mr4Mp2 can support MR1-2-3 and the MPs clients as well and SEPM MR1-2-3 and MPs can support Mr4MP2 clients as well.But it is not recommended
Will the MR4mp2 console support the MR4 clients?
Same as above
Since you have all laptops you can export the MR4MP2 package and sent it via Cd or put it on a shared drive for them to upgrade.
Do not use "Upgrade gorups with package" Feature to upgrade from MR3 to MR4MP2
and yes..do test it before deployment.