Yes. When you reinstall it will make another "build" folder next to this with another "build" name (and ask default setting for graphics). After the install and initial startup just change the path to the one you give above (your good one). The folder can actually be located anywhere as long as you change the path to it. Once you verify everything is working as expected with your original data folder you can delete the new one that TRS19 made on the re-install.
For reference, on the "Trainz Settings" > "Install" tab there is a button for an info page. It says "Instructions for moving your content" - It goes to a
Wiki page.
Before you do these type things it's always a good idea (mandatory idea?) to have backup. But then, you should always have a backup of your entire disk.
TRS19-Gold Plus-110491, plus beta-110771
WIN10 ASUS B450M-A/CSM, GTX 1060-6 Windforce
(and.. 2 Mac OSX installs, iMac MBP)