It has been a while, good to see TMO still rolling.
I have been daily driving Mobian first on a Pinephone, since my N900 put a red slash on the SIM in 2020, and lately a PPP.
Other than the miserable battery drain I really like having the ability to use websites which faded away as my N900 aged. I can do most anything I need on my mobile, especially with, the debian desktop apps, flatpak, and use of appified websites. I feel like the problem is unline the N900 there is not hardware abstraction layer for the system so too much graphic processing is done on CPU and the custom Rockchip CPU is plenty capable but if forced to do that work bo surprise it burns battery at about 3-4W even resting.
There are still some issues like integrating cameras(libcamera and pipewire config) on the Pinephone pro but overall except for the very short battery life in use I am really loving the Mobian on PP and PPP.
How is the Lest daily driver experience going?

If you have Pinephone Keyboard then Leste would be better with Pinephone. You Battery life is enough if you remember charge everynight and if it is heavy in use (streaming videos) over 8 hours in day, you should little charge when you take brake. And you have to take brake even you charge all time, because with Pinephone Keyboard charging speed from Keyboard side battery to Pinephone side battery is little slower than what "heaviest use" uses battery.

All though Leste is quite good with Pinephone, there is some things that can go better, example changing phone call volume during call you have to use Pulse Audio Volume Control. SMS messages works, but MMS not. How about Mobian those things?

Unfortunately the PP keyboard/battery has been discontinued. I had one but it was lost before the full function was realized, still was great.
Apparently there were hardware longevity issues which I suppose resulted in too many warranty replacements, not 100% sure.

I think Pine64 have to someday understand that many users only buy Pinephone if PP Keyboard is available again. At least my keyboard has worked over 2 years and I have used it lot.

IDK, I found that the PP or PPP in a modified otterbox case was fine in a pocket but daily driving a PP even with the extra battery in the PPkb was still crossing the line of too much for me too often. It made me realize that I didn't want a paperback book sized item in my pocket anymore. This said as a former N900 Mugen cover/Double-Scud battery user. The PPkb also doesnt have the tactile click response we loved on the N900, I am a blue kb switch kind of user,I like the tactile feedback to know I have made the keystrike. If I had another PPkb I would probably not use it everyday, but with full support in system we would really have t see if that were true I suppose.

Maybe have to ask Pinephone Maemo Edition from Pine64..just dreaming something like in N810 style, I don't mind if it would have smaller screen resolution and only one battery. I think that size can be possible that way, if they really want. But Maemo is Maemo experience only with keyboard.