insertHTML and dmImage templates

Hey guys.
I want our content creators to ONLY be able to use the insertHTML template for dmImage. Currently, the system pulls in all the image templates plus the insertHTML template (see screenshot). Other types do not do this by default. How do I remove the default image webskins.


That dropdown is referring to all insertHTML templates, including the ones
from core. Unfortunately, to remove them you would have to remove them from
core. You can also override them in your project to change the template /
template name.