@jeroen Right, gotcha. Ok. Yeah I sync mine manually, we press record at the same time on our own laptops, or as close to is as that, and I line them up for editing after. We also use Streamyard as our video calling app and that records the audio for each person separately too if we need the backup.
I've not seen an automation of that, but then i've not really looked. Sorry I can't be of help. Will boost it though as someone must know something.
@jeroen No problem. I don't know if you're recording at each of your ends too. What we do is count down to pressing record so we do it at the same time. That might work for your situation. Then you're only dealing with a fraction of a second or two in lining up, minimising the messing around.
Best of luck with it!