Both v14.2 do BSOD with Vega and 19.5.1 when I use -strap.

PAGE_FAULT_IN_NONPAGED_AREA
cmdrv64.sys

Strap Drivers are already in use when you load another instance of the miner. Here is log from b711 version :

01:37:11:329   fcc   Driver is not installed! Trying to install it...
01:37:11:373   fcc   Driver is in use, try to start miner with "-driver uninstall" parameter.
01:37:11:792   fcc   SSL: Imported 76 certificates from local storage

Rgds