The one thing that comes to mind here, at least one person (probably more) has expressed that the reason they like this idea is that they believe they could leave NeoLemmix unattended to record a whole bunch of solutions for Youtube.
Let me be clear that this would not be suitable for a completely unattended run, because replays don't contain any information on gameplay speed (normal vs FF vs pause-and-framestep), nor more importantly, any record of where the user scrolls the screen. Therefore, any video recorded this way without intervention would leave the view fixed on the entrance to every level, unless the person recording was manually moving it around still.
Or in other words: It'd be a tool to reduce some of the work with recording lots of solutions together, but it wouldn't be a 100% automation.
With this in mind, do the people asking for this feature still believe it'd be useful to them?