Manufacturer support is disappointing, subscription costs are high.
I thought the SVB user manual from 2021 was outdated and looked for the latest version on Garmin's website. But...
1. Here too, there's only an installation guide from 2021, not a general user manual. When you click on chat, the message "Not available for this device, please call, we will then forward you" appears. In my opinion, this is critical. Apparently, there are no software updates whatsoever. See https://support.garmin.com/de-DE?productID902860&tab/software. This effectively means that the initial software has not been and will not be further developed or optimized.
2. High subscription costs. The Product Overview brochure at https://static.garmin.compumac/Product-Overview_Cortex_1.3_GLOBAL.pdf mentions €20 per month and €120 per year. On https://support.garmin.comen-US?faqDcJ01Mk75I8MHXkanpSQn5 it says the Cortex Monitor subscription costs $20 per month or $160 per year! On https://www.garmin.comde-DEp916577 it says $30 per month and $240 per year. Aside from the price confusion, it's definitely steep for the rather limited functionality (the device itself plus a maximum of 5 sensors).
Sorry Garmin, theoretically a cool product, but it's going back unopened. Sorry for SVB, it's not your fault.