Opening a FactoryTalk 8.0 Project in FT10.0 without updating

I have a client's project file that is in FactoryTalk 8.0. We are currently running 10.0 and when I open up the project it wants me to convert. The problem is that I am going to build out our system in their backup locally then copy our files to their system while on site so I can't update the software version without it becoming incompatible with their existing running system. Is there anyway to work in an 8.0 environment without doing a complete install of FactoryTalk 8.0?

Your version 10 can create a version 8.0 .mer file (as long as you do not add anything which is not compatible with the earlier version).

Edit: If they are using version 8.0 Studio it will need to have been patched using the Jan 2018 or later patch rollup to open the version 8.0 .mer you create -- see Rockwell Knowledgebase Answer ID 1041447. This will not affect loading or running the .mer in the HMI, just their ability to open and make further changes.