...does this adjustment survive the LR-timelapse treatment?
Sure, only the parameters you decide to change in LR-Timelapse are modified.
Every other parameter stays like it is so are unsupported development settings.
My experience is that the spot removal/ cloning is lost if done early in the workflow, but is fine if done after all the other adjustments have been made.
However, if it is for sensor dust and there is a lot of movement in that part of the shot it can be horrible flickering spot in the video. I find that if it is really bad spot and has to come out, that it is best done with a fair bit of transparency in the the heal tool. Not perfect by any means, so a clean sensor or shallow depth of field are now my preferred settings.
Those birds though are a lot easier to work with.
{Not sure if this showing up as a new thread since it made me change the old subject line as being too long.}