If the jumps are based on the app/game design/script I check the F11-panel for their reason. Most often it's the number of visible entites or the flush time of the video memory.
Then i try to reduce these jumps by optimizing the game.
I never use fps_min. This may result in strange caluculation errors.
Sometimes I limit the framerate with fps_max to the monitors framerate.
Jumps not based on the gamedesign do not bother me.