Installed FL 20.5 (2019-07) into a new Win 7-32 bottle using the FL Studio 11 Crosstie. Installed okay (despite Warning at the end - choose: Skip this Step. Hope to create a new Crosstie for FL20 sometime soon.)
FL 20.5 seems to run okay but the file / plugin manager complains that it needs to NOT be run as Administrator. Running as Administrator complicates file permissions on Windows and can cause issues with drag and drop and opening some files. Crossover (through v18.5) runs all software as Administrator and Codeweavers Support has not been able to suggest a 'fix' for this in the current build. It has been submitted as a bug. Will test again in a later build.
You can select the "Don't show this" on the Warning in FL Studio and it seems to run okay - though, presumably, you may experience the Windows File permission issues.