The watches have a small battery compared to the phones. None of any of the three watch models I have had over the last several years has ever had more than a day and a half of life. I actually never expected anything more as my habit is to charge every morning anyway. It wasn't until my battery kept bleeding on my watch 4 that I even paid any attention to the battery life. When the battery is fully charged, if you go to the Wear app, it will tell you the expected remaining uptime based on your usage patterns (e.g. my watch currently says 80% 1d 1h left) and you can gage your booster timing accordingly. I also have a watch face with a battery complication, so I can see at a glance where the battery level is. The Ultra watches get more uptime because they have a much larger battery - something like 500 mAh as opposed to 300 or 425 mAh. You might be better off switching to the Ultra model.
You will not find anything on the FDA docket relating to application or appeals on the BP issue, as it is my understanding that Samsung has never applied to the FDA and has no current plans on doing so. I believe they added the capability mostly to use for other regions (as it is active there), and are still weighing the decision to apply for approval. It's a long process. Because they use the same hardware for all regions, they can legally say the device is "capable" even if it's not functional.
Good luck on on getting the raw temperature back. No one seems to know the logic they were using when they decided to take it away. This is a critical feature for many people. Everyone wants it back, or there is no point in even having the temperature sensor on the watch. The watch is capable, they changed the software programming. You can send feedback, adding another voice to the chorus, as the more feedback they get on an issue, the more likely there is to be some action. https://us.community.samsung.com/t5/Tips-Tricks/How-to-Send-Feedback/ba-p/3001692
Certain things you can do to extend, even by a smidgeon, the battery life is to lower the screen brightness to a level where you can still easily see it, but not at the brightest setting. You can turn off sound for notifications and just use vibration, or sound instead of vibration (I think vibration uses slightly more, but few people want their watch making noise), or turn off notifications to the watch entirely, if you usually have your phone nearby where you can hear the notifications.
