In the case that you would run two versions of Fabric, you would need the latest version of OptiFabric and a version-specific file for each version of OptiFine you would use in the Mods folder of your Minecraft installation. As of the moment, if you were to do this, every time you run Minecraft with OptiFabric installed, it will only check the highest version of OptiFine, and if you are running an different version of Minecraft than the latest version of OptiFine, the game hangs on an exception:

There was an error loading OptiFabric!
This version of OptiFine from [Installation Path] is not compatible with the current minecraft version

Optifine requires [OptiFabric version] you are running [Highest OptiFine version in Mods folder]

This is because all OptiFine files must be placed in the root Mods folder. If it was also possible for the mod to check the subfolder of the current version (as Fabric checks these for version-only mods), such as:

[Minecraft Installation Path]\Mods[Current Version Number]\OptiFine_[Current Version]_[Current OptiFine Build].jar

...or if the mod can specifically check for a version for the Minecraft build currently running, then it would work. Please make this consideration in future builds (where possible).