I've made a bunch of templates for after effects, with comps where the frame rate is 25 fps. But I now have a multiple projects where I will be using 50 fps. When I import my templates everything is double speed.
My question is. Is there a way to convert those 25 fps templates to 50 fps, so that I don't have to try to use time remapping or something else to match the speed, once I import the templates?
Keyframes are based on time, not frame numbers. If you change a 10-second comp from 8 fps to 120 fps, it will still be 10 seconds long. There is nothing you have to do to the comp but change the frame rate. The timing will not change, your files will just be twice as big, and the average YouTuber that watches the files will probably still see them at 25 fps because YouTube throttles the data rate, the resolution, and the frame rate based on their best guess at the viewer's connection speed.