Can you provide more information on how your installation of PureOS that was present by default “didn’t work out?” Another forum user in the past few days described having some kind of unexpected issues with PureOS on their Librem Mini v2 but I did not understand fully the nature of their issues or what caused those issues.
I have a Librem 5 handset and a Librem 14 laptop, and I am writing to you from a PC that I built in 2018 that I installed PureOS on. I also reinstalled PureOS on this PC on Friday, and reinstalled PureOS onto the Librem 14 last month from the flash drive that came with my Librem 14 a few months ago, although the flash drive was re-imaged with a newer download of PureOS [not the same installer image that I got it with].
So I have these similar experiences. And I am sure other forum users have similar experiences. We might be able to help with good response time, but for example I don’t have a Librem Mini device. (Also, everything seems to be working fine for me, including the PureOS install that was present on my Librem 14 laptop by default.)
Edit:
So, what I’m saying is it might go a long way to describe the nature of your problems in as technical a way as possible.