Online chastity and self locking discussion

Hi there! I usually keep my boyfriend Chris locked up for at least six days a week, and we do regular bondage sessions too. But I have to go traveling soon. I want to maintain control over him, so I’ve been thinking about remote keyholding with a smart safe. I remembered the kind of keysafes from my old job and was happy to find them on Amazon! The price is a bit high, but I spotted a Masterlock smart key safe and wanted to know if others use these? Because it’s expensive, I’ll need to save up until later when I’m away. Ugh! I’d like the lock sent directly to my friend so she can set it up for Chris. Does anyone know if ownership transfer is possible back and forth as needed? Since my internet might be spotty while traveling, I want the option to switch control back to my friend for safety. The online documentation seems limited. Not sure if links work here, but I’ll hold off on posting them. Other alternatives to Masterlock would also be great (I’ve seen some poor reviews of their app!). Any advice on other options that allow ownership transfer and are available in the UK? This seemed like the perfect place to ask; hope you don’t mind! Thanks!