There is a way, I found that the data is stored in a sqlite database in
C:\ProgramData\Twitch\Games\Sql\GameInstallInfo.sqlite

MAKE A COPY OF THE DATABASE FILE ABOVE IN CASE ANYTHING GOES WRONG
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Download DB browser from https://sqlitebrowser.org/
Use it to open the database file above

Click on tab Browse Data and select the table DbSet, now you can see all the games and where they are installed, last column is the game name

Go to tab execute sql and execute the following
In this case I simply want to move the games from my D to E drive

So D:\Twitch\Games... will become E:\Twitch\Games...

Modify the 'D:\', 'E:\' to suit your needs, the command will modify all the rows

Command:
update DbSet
set InstallDirectory = replace(InstallDirectory, 'D:\', 'E:\')

When you are satisfied with the results, click on Write Changes below the menu to save to the database file

Copy the game folders from the old location to the new location
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