Can I have two version of SCA installed? Right now we are on Elbrus and going to make the transition to 2020.1. If I install the 2020.1 bundle will it override any of the setup/configuration for the Elbrus instance? Or can I just install this and run both versions concurrently using different domains.

Yes. If you want two entirely separate websites, you will need two Web Site Setup records, which will require two SCS or SCA licenses. You can do it with a single Web Site Setup record, but both websites will share the same setup record. When 2020.1 is installed, it will not overwrite the Elbrus bundle, and it will create separate SSP applications from the SSP applications used with Elbrus. When deploying the SSP applications, link to the domain not to the site. There are probably other steps to get two websites to work on a single web site setup record.

Assuming you are migrating the website from Elbrus to 2020.1? If so, just create a development domain and link the 2020.1 SSP application to the development domain. Also, don’t forget to attach a robots.txt file to the development domain so the domain is not indexed. Good luck!