Just to check, if you are using a Hero 7 Black in the Karma Grip (not in the drone), the actual Karma Grip handle has to also be updated using the USB-C connection and Quik on a computer.
I may be wrong, a while since I tried but doesn't it store a lot of data in the video files using the space for extra audio tracks.
Dashware used to extract it and it included motor speeds, height, distance, etc
In the UK the official website to start at is at Introduction - Dronesafe
It also has an app which shows airport and other no fly zones and if any special events are on e.g. airshows.
If you can avoid any people. After Gatwick don't be surprised if you see fists being shaken at your drone and...
For best picture quality my Phantom 4 Pro V2 wins with its 1" sensor and also wins on flight time and range.
But nearly as heavy as Karma and three times the price.
The non linear video from Karma in 4K is a let down but it can sort of be fixed in some video processing suites.
They do have a manufacturing date on them thus one can check stock age.
Not sure about Karma flight batteries but other makers drone batteries smart electronics discharge the battery to optimum storage charge level after ten days.