I too tried a lot of frames today. To test it. As you know, we increased the limit to 10.000 frames when doing a New Scene. This resulted in AP hanging for a minute when I made an original drawing somewhere in the middle – or drew a few lines, etc. This is not supposed to be that time-consuming, so we should be able to optimise this a lot. On the other hand, it is not normal to have 5000 frames or more present at once. Normally you would split your music video into clips/scenes, which is much more manageable for a multitude of reasons.
You could start doing an “animatic” (like a storyboard, timed out to your music to give you the overview and impression of how your video is going to be) – this could be done with only 1 or a few frames per second (FPS), because you don’t need higher precision. This way to can plan and edit your whole video with ease using far fewer frames. Then, once that is done, you do one scene (or a sequence of scenes) at a time. Again keeping the number of frames to a manageable number. When all scenes are done you edit them together using any video editor which also gives you access to transitions, wipes, etc. Much better this way.