The code path for Type 4 print drivers will be to first generate an XPS formatted spool file.
All print jobs will first be XPS, then the print filters defined in your driver will be loaded by printfliterpipelinesvc.exe and the XPS file will be converted to the PDL, Printer Description Language, the printer supports.
When this is a shared printer, since no software is ever copied to a client system when a printer is shared using a Type 4 driver, the client system will bundle up XPS and copy it to the server and the print server will convert the content to PDL.
Why is the file size causing an issue?
Are you seeing the XPS spool file at the 500MB or the PDL spool file?
@Limitless Technology is correct with regard to the driver path, the spooler will load Type 4 print driver directly from the driverstore. There is absolutely no reason to move these files to any other location.
prn* are the in box drivers.
Directory of c:\Windows\System32\DriverStore\FileRepository
11/11/2021 04:16 PM <DIR> prnge001.inf_amd64_1daeee8f3aa30fcb
11/11/2021 04:16 PM <DIR> prnms001.inf_amd64_8bc1bda6cf47380c
12/14/2021 08:03 PM <DIR> prnms002.inf_amd64_14b6fbd636fe2b5b
11/11/2021 04:16 PM <DIR> prnms003.inf_amd64_0e2452f597790e95
11/11/2021 04:16 PM <DIR> prnms003.inf_x86_360f6f3a7c4b3433
11/11/2021 04:16 PM <DIR> prnms004.inf_amd64_c28ee88ec1bd4178
11/11/2021 04:16 PM <DIR> prnms005.inf_amd64_add71423ba73e797
11/11/2021 04:16 PM <DIR> prnms006.inf_amd64_c3bdcb6fc975b614
11/11/2021 04:16 PM <DIR> prnms007.inf_amd64_8bbf44975c626ac5
11/11/2021 04:16 PM <DIR> prnms008.inf_amd64_69b5e0c918eab9a6
11/11/2021 04:16 PM <DIR> prnms009.inf_amd64_a7412a554c9bc1fd
11/11/2021 04:16 PM <DIR> prnms010.inf_amd64_9e410195c3b236c9
11/11/2021 04:16 PM <DIR> prnms011.inf_amd64_f83138380f5fb6ab
11/11/2021 04:16 PM <DIR> prnms012.inf_amd64_707d3849370b9d23
12/07/2019 01:13 AM <DIR> prnms013.inf_amd64_2b1aa5c0f193f278
11/11/2021 04:16 PM <DIR> prnms014.inf_amd64_faec3fc366f8e1fa