Make the last frame in "Effect Controls" be the final frame of the clip you're working on
When you go to the effect controls and put a keyframe at the far left and far right of the keyframe "timeline" within the effect control panel, you'd think you'd be putting a keyframe on the first and last frames of the clip that you're working on. But in reality, the far right keyframe doesn't affect the clip, as it's one frame beyond the last frame that's actually in the timeline of the clip you're working on. You also can't see what changes you're making with that keyframe because, again, it's looking at a frame that doesn't "exist" as far as the current length of the clip stands in the timeline. People habitually go to the far right of that keyframe line and then cursor one frame back to actually affect the clip they're working on, but why should we need to do that? Why have a frame that we can't monitor or control show up in the effect control window? I'd like the last frame of the clip that I'm working on to be the last frame that appears in the Effect Controls window.
Oliver Siegel commented
I agree, this is often a problem. Keyframe at the end of the clip, and you can't see your effect changes, plus the keyframe doesn't really show because it's cut off sometimes... It can be quite weird...
Perhaps a good way to implement this would be to actually make that last frame greyed out / not select-able (kind of like when you have a sequence in your timeline, that's longer than the contents of that sequence)
So rather than to *show* the last frame as suggested by the OP it might be best to make the last frame not selectable, since showing the last frame isn't in line with the usual behavior.