Do action x after y filament length/minutes/layers/height

This is sort of a follow up on the discussion here.

Are there any plugins, which you can set during the print, to do an action after a certain time/height/filament length/whatever...?

For me (and I think for at least some others as well) it would be nice to adjust some settings during the print. Many times you want to change that particular setting right away. No problem, you can use the controls or the command line for more advanced stuff.
But sometimes you want to speed up the current part, but you know that after x layers you have to slow down again. Then it would be so nice to already 'queue' that setting so you don't forget to change it back.

Most used and common would be "Do x after layer y", but to make it more generic I would say "Do x after y minutes/layer nr/object height/filament length".

Maybe there are even more option for 'y'...?!

any ideas?
(don't know if it is appropiate to say, but I might be able to find some budget to create the plugin)

cheers / joris