The feature Custom Template is great, but is hard to design a template with all the possible options.
Please create something like an "Custom-Template-Builder" which creates all the needed tags similar to the builder for a view/custom-view.
In addition, it would be very helpful if you could create something what is able to generate a custom-template with the standard settings.
With this feature it would be very easy to make slight changes on the generated template. It also helps to avoid typos when developing a custom template with the parameters and settings which are possible.
It could work like the "without header" function in generating the files. Just a additional column with a checkbox which is generating the custom-templates based on the field setup.