What you’re describing sounds like an issue with either A-GPS (a mechanism by which sat navs can receive initial data over a cellphone connection, without which the initial location search can last up to 10 minutes, but afterwards it will be as smooth as always) or approximate location (a mechanism in which Google uses a huge database of cell tower and Wi-Fi data to quickly get your approximate position).

I would suggest checking the permissions on the OSMAnd app – maybe it’s lacking something that Google Maps has?

Browser integration works on my machine, which also uses Wayland, so unless you’re, say, running Firefox from a flatpak or something, I don’t see why it shouldn’t work.

It seems like on Invidious, the default setting is to still have the end user load the video directly from YouTube, whereas Piped defaults to proxying the video through its server as well. I would imagine this makes Piped servers a lot more noticable to YouTube.

It not only is still an option, it’s the default option.

Haven’t used Chrome or Chromium in quite some time, but sounds interesting – especially since fully open-source forks of Firefox, such as Fennec, can use Mozilla’s sync service.