I got following message in mrinstaller.log on a PW5 (2021), device code 21A, FW 5.16.2.1.1.
Spoiler:
**** **** **** ****
[2023-11-09 @ 22:05:44 +0058] :: [MRPI r19303] - Beginning the processing of package 'Update_librariansync_20201109_kindle5.bin' (librariansync 20201109 kindle5) . . .
Package 'Update_librariansync_20201109_kindle5.bin' (librariansync 20201109 kindle5) is not targeting your device [82A vs. 11
0F
10
24
1B
1C
1D
1F
20
D4
5A
D5
D6
D7
D8
F2
17
60
62
5F
61
C6
DD
13
54
53
2A
52
201
207
206
202
205
204
293
26B
26C
294
26E
26F
20C
20D
21C
219
21B
269
26A
2E8
341
34A
342
2E1
2E6
2F7
366
361
362
402
363
4DB
4D8
4DC
4DD
403
4D9
4DA
414
3D1
3AB
3CF
434
3D8
3D6
3D5
3D4
3D7], skipping . . .

I hope that can be easily fixed. Thanks in advance
Update: After checking out the first options in KOreader, which I started to be in love with, I understood how books are organized there. Simply folder wise, which is exactly what my wife loves. On top you can use the meta data library of Calibre in KOreader to find books in another way.
Last but not least, using my Raspberry as Calibre server and connect it with OPDS is the cherry on the cake.
Thanks to all who spend/spent there personal time to make user like me happy. I will do some donations in the coming days to honor that.