This is a suggestion. Nothing being a Startup has to build an eco-system of app on android.
However the FIRST Product is always the Break or Make for any company.
Nothing Phone 1 was the First Phone from the company.
However after android 15 it wont receive any major update.
So here is a suggestion.
If you can ask the users a very nominal amount which justify your software team and resources to keep on providing Android OS Update till the time its possible for OLDER Device like Nothing Phone 1 and by next year Nothing Phone 2 on a Paid Plan like a small subscrition fees so that the older device continue to receive all the OS Update and Android Security Update till the time device is capable of supporting it (Around 5 to 6 years).
And YES, Please do provide the Battery Replacement option open for Nothing Phone 1 after 4 Years please.