The RC does not really the exact functionality you describe, but there are two methods that should help:
There is an option to set tool defaults: by clicking the icon of the tool you want to change in the toolbar once. You can set the default size and style (background, padding etc..) of new tools. Note: before you can save the template, the tool will require a name. Now all the new tools you make will have the default setting. It will not effect older tools.
Alternatively, if you need more flexibility, you can actually also use normal tools as a kind of "prototype". The way I do this is by creating a special page within the exposition (not exposed to the reader) with empty tools styled in the way you need, then copy paste these whenever you want to use such a template/prototype. If you keep that "prototype" page open in a separate (or pinned) browser tab, you can copy paste without the need to switch (and wait for loading of) pages.
hope this helps!