I didn't take time yet to watch the longer video, but there are a few things to mention about the shorter one. He doesn't mention taking out the adjusting screws, nor cleaning the carb at all. I like to use WD-40 to blow through each and every passage in the carb, verifying that each passage flows. I used to use carb cleaner for this, but if you are working on a Zama carb, the carb cleaner can instantly destroy some of the check valves in the carb. So I just switched to using WD-40 and/or compressed air to clean out and check flow on the various passages.
He also doesn't mention checking the needle lever height, which one should do. And lastly, he put the regulator cover back on improperly. When he took the carb apart, the hole in the regulator cover was pointing towards the mixture adjustment screws. He put it back with the hole off to one side. In a machine such as a leaf blower, weedeater, chainsaw, etc., this could put the hole facing into the cooling airflow, causing the carburetor to go rich, especially at higher rpms. Same thing with a model airplane. If you point that hole forwards, the prop blast and/or flying airflow can pressurize the carb regulator through that hole and cause you tuning problems.
AV8TOR