It's not like you can't do it (I did save the original SSD and replaced it with a new one and installed TrueNas Scale). It's just not intended to do from uGreens perspective.
Edit: I think I used either of these guides I used on how to open and how to install the new OS:
https://youtu.be/BWNH_JzMNPc
https://youtu.be/R8t-Wqx_E3U
https://youtu.be/yh8Ao5ryOeE
Oh yeah. The HDD indicator bays are partly non-functional as well.
But you can restore some functionality with scripts you run periodically with cron. Juat search "ugreen dxp4800plus led cli github" to find it.
Edit2:
And I only chose a uGreen NAS due to the Kickstarter price. Because that was a 40% price reduction.
At least I got a solid Model that is really nice. It also has a magnetic metal dust cover Ican easily remove if needed (even easier than the one on my pc case front panel which is a Fractal Design North)
And I'd argue the same applies to the iMessage vs RCS (or actual non-SMS messengers).
Most normies would most likely not switch as they could care less about their data.