Can you assign template on account by account basis?

Is there any way to use a custom template that can be assigned to be used for a particular account or set of accounts, and all the rest use the default template?

Thank you for asking. There is no option to assign Email Template for a particular account. We will take a note on this.
When sending an email from RangerMSP, you should be able to select another non-default Email Template using drop down list on the Email button - this option was introduced in one of the recent versions and is not available in older versions.

Hope this helps.