I have done this about two years ago but the concept still works, but collecting dust on the shelf.
The only downside was: on my S7 I could only run Linux on top of Android in a chroot (with the Linux Deploy app) and there were a few limitation:
no 3d acceleration as I had to connect to the chroot with VNC
I could not make cups working with my network printer (probably this was kernel related as I got it working on my Galaxy S2 with a similar setup, but the S2 was much slower and it had other limitations)
on newer Android roms I lost sudo (root only worked if I sshd into the chroot as root)
That is NOT what i want. I did that kind of chroot on nexus 4 about 6 years ago. Although it did not have power to USB port and you needed Y cable for it. That is not usable. I meant chroot on top of SFOS which is much better. Posmarket os on the other hand is real linux without android that's even better. Problem is we can't have video output on these devices YET.
No idea how to get the keyboard installed, without a keyboard, but i used xvkbd via apt-get to type @ since it is missing in my 3rd-level-less hwkbd layout.
On Performance, the Nexus 5 is roughly 4 times slower in storage access than the Proš.
Nexus 5 is 4.7Mb/sec read speed and Proš whooping 18.73Mb/sec according to sysbench.
Jolla Phone was only 1.14Mb/sec.
Memory speed is only a bit faster on Proš:
Proš 403.3 Mb/sec
Nexus 5 375.23 Mb/sec
Jolla 1 195.15 Mb/sec
Calculating prime numbers up to 2000 with two cores:
Proš 3.77sec
Nexus 5 5sec
Jolla Phone 9sec
Now half that time for nexus 5 with quad core and 1/4 the time for Proš with octacore should give a rough idea why xfce lags on Nexus 5.
As they say it's faster in both ways RAM and Storage. Also it's crazy mod 3 GB RAM + 64 GB STORAGE on nexus 5. I wish i could do it. I only have done battery mod on nexus 5.
i have a problem with option menues in apps. even when the app is rendere ok, the buttons and dropdowns in settings menu are way to large, so most of the settings are out of the screen and not reachable. i am not sure, if this is because of missing style in sfos or wrong dpi setting, may be it is only a missing environment variable?
If this is happening in all applications within XFCE4, I would say it looks like a DPI issue, however for me altering the DPI changed both the menus and the application windows, so I am surprised that only one of those is off in you case. You can have a look in Settings > Appearance > Fonts. My DPI is set to 160 on a 2160×1080 display (the UI is quite small with these settings but I like it).
There is also a Window scaling setting in Settings > Appearance > Settings, mine is set to 1× but I know some prefer having it set to 2×. Be careful not to set it to 2× if your DPI is already set to make the UI look larger, otherwise the windows won't fit in the screen anymore and it will be difficult to change the scaling back to 1×. If that happens, you can move windows using Alt+Click if you have a keyboard, or using the window menu (click on the left icon in the title bar).
If stuck after changing the above setting, you can also change the window scaling factor in Settings > Settings Editor > xsettings, and the option will be on the top plus you can navigate through the individual options using the up/down arrows of a keyboard if the options you want is out of the screen. The DPI settings are also in this settings page, if you scroll down.
If you are unsure, just make a backup of you ext4 file in the sailfish_ubu_chroot folder before altering the xsettings.
As they say it's faster in both ways RAM and Storage. Also it's crazy mod 3 GB RAM + 64 GB STORAGE on nexus 5. I wish i could do it. I only have done battery mod on nexus 5.
Two years ago i mod my Nexus with more RAM too.
I can show you if i find it :-)
I don't have video out on the Proš either, although the hardware should be there (through USB-C). I heard that elros34 managed to have video output on a SFOS port on the Photon Q, so there is hope and it may already work for some devices, but don't know who has the motivation and skills to work on that on the Proš.
sailfish_ubu_chroot with xfce4 does not rotate either; or it does, but it will just fill the top part of the screen and will be cropped on the right due to non-matching ratios. This is a non-issue on the Proš though, since I only use Ubu chroot with the keyboard open (I almost never have to touch the screen with it, I mapped everything I need to custom keybindings). However I remember seeing a post by n950 here in this thread that showed chroot and a desktop environment in portrait mode. I don't remember which device he was using or how he did it, but I believe n950 is still an active user here. [Edit] Or maybe that was Jakibaki?
Performance on the Proš is nice, but I don't know how it would be on older devices. I remember Easydebian was a bit too slow on the N900, and I haven't really tried chrooting with devices whose performance was somewhere between the N900 and the Proš. I did on my Jolla C and I think it was acceptable, but I barely used it due to the lack of hardware keyboard, so can't really say.
