There is a setting in ON1 that substantially resolved my issues with the NVIDIA driver conflicts. In the main menu (on the top of the ON1 opening screen), under Edit, choose Preferences. In the Preferences window, select System. Then select the System Tab, and look at the AI Processor option, which is a pulldown list. The default is probably Auto; change it to the NVIDIA driver. By the way, I use a PC, but my understanding is that the Mac version of ON1 is very similar.

I am very happy with ON1, with the exception of their customer service/support. The conflicts with the NVIDIA drivers have been going on entirely too long, and their ostrich-like responses (or lack thereof) makes appear ON1 to have their heads in the sand, with an attitude of indifference. Also, I am familiar with the realities and economics of phone support, particularly for complex software. Some companies have customer support available on fee-based support options. Of course, many users want free support, but there are users (like me) whose time is more important than their money, albeit at reasonable levels that are high enough to make economic sense for providers.

Hope this helps...