Is there a way to remove them from the list?
Couldn’t find a way to delete them from the GUI, but found the presets as JSON files in "C:\ProgramData\Topaz Labs LLC\Topaz Video AI\presets". Moved them out of there with VAI shut down, but, different from custom presets, the factory presets are restored on restart.
Don’t think that this makes much sense, unless Topazlab claim to know which pressts are mandatory for all their users, do they?
Does nobody answering mean that there is no way to remove the factory presets from the Preset list?
In this case, please add a feature to remove (or hide) the factory presets from the Preset list on demand.
I don’t need those either but found no way to get rid of them yet to be honest. 
maybe try marking this folder as read only or set folder NTFS permissions to deny write access. not sure this is a smart move, but it might work without braking anything.
Honestly, what I don’t understand at all is that when removing the factory presets from the folder, VAI recreates them on restart. There must be someone at Topazlabs who is convinced to have created the most brilliant presets on the planet, worth to protect against any user interference by all means.
