Not sure if what you want is an option.
Try to find the manuals, there's something with having an RGB monitor on the DB32 port for the toaster card to properly function. Is the card going into an A2000 or A4000? The toaster is fun to work with, but you'd have to be willing to step back to the lower video resolutions that it requiers to work with it. Best bet, get another Amiga and make it Toaster specific...