iBasso DX90 Rockbox v3.15 issues

[peterz]

Hi -
I apologize if this isn’t the correct place to post this (if it’s not, please direct me to the right spot/person).

I recently acquired an iBasso DX90, primarily because it is a good player that can be Rockbox’d, though it’s not an officially supported build.  The user interface on all the new players I tried is abysmal & can't even do the simple things I need. Anyway...

I installed the patched bootloader and firmware (v2.5.1) that was on the site napych.com, as well as a patched version of Rockbox there from June 2015 (v46f8e0e - 150609).  It doesn’t say, but probably Rockbox 3.12
This works fine.
My problem: Since this Rockbox is several versions behind, and I thought there must be many improvements in the last 6 or 7 years, I installed the latest compiled build I could find for the iBasso DX90 (Dec 29, 2021) from the daily development builds site.  This breaks at least 2 things:

1) the battery indicator always displays as if it were plugged into power, on any theme I use.  I can see the battery % as a number if the theme displays that, or on the status bar if shown.
2) Under Display-LCD options the “Backlight Exemptions” settings do not function.  They have been enabled, but that makes no difference (and they show as being enabled and selected in the .cfg file),  - pressing a (say) volume key still wakes up the touchscreen.
(Re-installing the old Rockbox version fixes these problems so it's not a sudden hardware issue)

I could live with #1, since I can see a percentage if I choose, but #2 is an issue for me, since I need to be able to turn the screen off, put it in my pocket, and still adjust the volume or press pause (leaving the screen turned off).
This I can do with the originally installed older Rockbox version and it’s mods.
However, there are some things I do like in v3.15 (such as easily get information about a song (primarily the artist) while viewing the playlist - and I don't understand how to modify a theme to show that information in the playlist viewer. If someone could explicitly direct me on how to do this I would appreciate it.)

So -my questions (since I doubt any fixes are forthcoming shortly, though that would be wonderful)
1)  am I missing out on any important functionality by keeping with the much older version? I don’t care about plugins,  or anything but stability, power mgmt, sound quality & playback usability.
2)  •  Where can I find the originally released v3.15 (or 3.14) Rockbox for the iBasso DX90 that is already compiled/built (I do not have the facility or environment to do my own build)?
• Is there a v3.15 (or other more recent) of Rockbox for the iBasso DX90 that doesn’t have these issues? Where can I find it? I can only go back a month or so on the daily build site, and these problems are there as far back as I can go.  Do these problems exist even in the original release?
• Does anyone have a right functioning build (of any newer version) they can send me (and will you please)?
• Is there a better place or person to ask these question of / notify of these issues?

Thanks
peterz