At Christmas Expo last week, I attended a session on Drone photography. When the subject got around to sync'ing up all the camera footage, I mentioned that I use PluralEyes software from RedGiant. It got great results for me in VERY little time (just some simple editing once the software did its instant work). Just now, I got an email that TOMORROW, July 30 is their one day only SUMMER SALE.
https://www.redgiant.com/blog/2019/07/23/coming-soon-summer-sale/
Plural Eyes 4.0, which normally sells for $299 (USD), and is NOT a subscription, will sell tomorrow only for $179.
For some of you, that is a hefty price, but for the time saved in sync'ing your lightshow shots, it is well worth the money (my opinion). Check it out.