I know that this is not a RoboChamps issue, but I think that you should suggest that each MRDS version would be installed in a different default folder, like MRS.
I had MRS 1.0, MRS 1.5 and MRS 1.5 May in my machine working with different respective MRS packages.
If each MRDS version install in a different folder and all packages for that version too, we should have no problems with new MRS releases.
Complementing, I also suggest that older MRDS releases be available for download. This way a newcomer should just download compatible MRDS and packages to try an older challenge. And you will not need to "upgrade" the packages to new MRDS versions.
Again, I know that this is not a RoboChamps issue, but I think that you should consider asking for this....