[kami]

... like possible in the network interface.
why not in the normal render engine?

[m-Que]

If I understood you right, you can already do it right now -
while rendering, hit 'Stop' then change the SL to the one you need, then hit 'Render', select 'Resume', and you're done.
Is this what you're after?

[kami]

almost ...
I always fear there is a small possibility that it cannot resume the render (which happens sometimes, not very often). PLUS you have to wait a while after the stopping before you can resume it.
And you'll lose time

[m-Que]

Yeah, that's true...
Anyways, gotta be careful - when stopping the render for resuming, make sure the _tmp .MXS has not been changed or is still there. Otherwise you might get an error message saying that the scene has been modified and you'll have to go all over again from the beginning.