If marbles roll under the chain lift while it is still operating, the marbles get stuck and then you will realize that more marbles get lost. Usually, this is due to the marbles falling off the track and then rolling under the chain lift (when using MplusM's addons).

A small addon fixes this problem by designing a simple arc piece that almost interferes with the radius of the chain lift bottom pulley. With this, the marbles gets carried back to the marble run as if nothing happened. I have shared pics of how to assemble it. However, if you think that you cannot assemble it inside the base/have not printed the base yet, print the combined base instead (not included in the print profile because this part is untested, but attached on this model (only downloadable on computer)).

EDIT 11/1/2025: I just realized that it may be better to print it on its side to make a smoother curve and not a rough one. I have updated the print profile to have another plate that prints on its side.