I get that vivo phones aren't supported, but the energy and messaging is very off here. "Vivo - no, lol" "open an issue or buy pixel".
There's no need to be a condescending dick to your users, you can just write "phones with aggressive task managers might kill the app and break updates".
Plus I don't think anybody sane is "buying pixel" just to access a widget app. ๐
I have a Xiaomi, which typically is on the bad list of "dontkillmyapp" but with a bit of knowledge and care I've had zero issues.
You just have to know not to let the phone kill apps if you don't want them killed ๐คทโโ๏ธ but I guess many users can't understand that.