When I wanted to verify multiple Ruby versions of Windows, I posted it because it worked by passing the path to the junction.
For example, suppose you want to verify Ruby2.6 (x86) and Ruby2.7 (x64).
First, download the Ruby2.6 (x86) installer from RubyInstaller, and select C: \ Rubies \ Ruby26 as the installation destination to install it. At this time, the pass is not passed.
Similarly, install 2.7 (x64) in C: \ Rubies \ Ruby27-x64.
Create the following batch file in C: \ Rubies.
use_26.bat
rmdir RubyCurrent
mklink /J RubyCurrent Ruby26
use_27_x64.bat
rmdir RubyCurrent
mklink /J RubyCurrent Ruby27-x64
Double-clicking on use_27_x64.bat creates a junction named RubyCurrent.
Finally, add C: \ Rubies \ RubyCurrent \ bin to your PATH.
This allows you to switch between Ruby versions as you like by running a batch file.
If you want to use Ruby2.7 (x64), double-click use_27_x64.bat, and if you want to use Ruby2.6 (x86), double-click use_26.bat.