@Mark C Julian, if that was aimed at me then yes, with the instructions how to do that.
It was targeted at everyone/anyone that is experiencing the slow down but here's how.
Make sure Xojo is not running.
Open a terminal window and cd to your Desktop
Copy the following command to your terminal window, this will create an approximately 6GB ramdisk formatted as HFS+
diskutil erasevolume HFS+ 'RAM Disk' `hdiutil attach -nomount ram://12582912`
Drag your entire Xojo 2019 Release 3.1 folder from your Applications folder to the RamDisk with the Command key held down to ensure its moved and not copied, you might need to enter your password to perform this action.
Give xojo a few starts by double clicking it directly from the ramdisk to make sure that everything is settled down then try your usual routine that shows a slowdown and see how you get on.
When you are done, you can move it back into the Applications using the same drag with Command key held down and confirm the move with your password. You might get an error saying the copy took place but not all files could not be deleted, check the ramdisk and see if the Xojo folder is empty then you can delete it manually.
To remove the empty RamDisk, right click it on the desktop and click Eject.
Could you then repeat all tests on an APFS ramdisk with the following command:
diskutil erasevolume APFS 'RAM Disk' `hdiutil attach -nomount ram://12582912`
Note: When you mount the drive, it if doesn't show on the desktop and open its drive window check its there in Disk Utility, click it, then click Mount.