I don't know if this is quite right fix.

If efra is set to 10, frame 10 will still be rendered, while strip, that ends at frame 10 won't - resulting in black frame during final render.

Try to play this file with patch applied - result will be unexpected

I don't know if this is really possible to resolve. If you run set end frame based on what you see in preview, render result will correspond with that. (user will say, "I want this to be my last frame")
While if you set end frame, while looking at timeline you have to take into account that rendering at strip end won't produce image. (user will say, "I want animation to end here")

Since we can't tell what the user is looking at while setting end frame, we can not make simple correction in algorithm.

Question is whether to reclassify T67499 as design issue, that can be solved or close right away as can not be solved.

I can only imagine drawing playhead as 1 frame thick rectangle to represent this offset so everybody would understand what's going on. But quite often we work at zoom levels where this wouldn't really help.