If not changed Keep Last

I was just thinking, FF can take a while to load with some filters, If im right in guessing FF will load the last used/selected filter from the library on loading of the program, rather than loading up an image that might have already been loaded fully in a previous session why not make it so that if not changed it keeps the last render rather than slowing things down and doing it over again. Or at least put that in the options somewhere i for one would find that usefull in terms of efficiancy/speeding things up, what do you guys think?

The same could apply to all filter selections in general when choosing between them as i don't think it needs to reload each time unless somethings been altered. It's only when one goes to edit or moves some param sliders ect that i think it needs to reload.