In the video you can see a problem with taking down the gennaker. Sailing boat was 45 feet long Salona 45 which is a good mixture of luxury and performance.
just release the tack line first and you're left with a flag that is easy to collect. whenever possible set main and jib, tack, leaving the asym on the inside and let your jib do the work for you.
You're making it harder, not easier, by not raising the main. It's much easier to take the gennaker down in the wind shadow of the mainsail. Also, big drop on the halyard --- maybe 15 to 20 feet --- will depower the sail. Then gather it in quickly, then lower the rest of the way
nice to know that even "experts" get it wrong, sometimes (only HUMAN after all); but there is a BEST way: to use a sock, let go the sheet, lower the sock, (under the genny/jib), then lower the head of the sock/sail neatly, no flogging around, and you only have a "limp sausage" to deal with, not a solid disc the size of a front yard!!