L310: rooted but unable to install CM12.1 - Error-Message included

Hi,

after giving 4.4.2-StockROM a (long) try, I wanted to install [SM-T31X][5.1.1] CyanogenMod 12.1 unofficial build (by tohenk).
I followed the instruction for TWRP-Installation and the one for CM12.1 by tohenk.

Doing so, I installed TWRP via Odin 3.09 (successful).
To root the T310, I had to install the zip "ROOT_SGT3_8.0.zip". (also successful)

Reentering TWRP to flash the CM12.1-zip, I selected the file from internal SD-Card, getting a warning that the file shall not be compatible - having had the same with the root-zip, i swiped to install.

Resulting in the error (got a screenshot, but can't link it - to few posts):

"Can't install this package on top of incompatible data. Please try another package or run a factory reset.
E: Error executing updater binary in zip '/sdcard/fw/cm-12.1-20151018-UNOFFICIAL-lt01wifi.zip'
Error flashing zip '/sdcard/fw/cm-12.1-20151018-UNOFFICIAL-lt01wifi.zip"

... as offered by TWRP, i reset the Dalvik-Cache, rebooted. All Apps have been reinitialized, rebooted again into TWRP, getting the same Error.

So I installed philz_touch_6.08.9-lt01wifi.zip - but getting the same Error...

At the moment, I'm stucked with rooted StockROM...

..what did I miss?
(thanks for any help)

[Q] [MediaTek] [SPFT] What is included in file "bplguinfocustomappsrcp"

When I download a SPFT flashable Stock Rom, there's always a file beginning with "bplguinfocustomappsrcp" included.

To correct the IMEI after a flash, MauiMETA uses this file as NVRAM database.

But what information is included in this file??
Can I use the NVRAM database file from the Stock Rom from Device A on Device B, as long as the SoC is the same??
There muste be a difference, mustn't?

For example, I have these file:

BPLGUInfoCustomAppSrcP_MT6582_S00_MOLY_WR8_W1315_M D_WG_MP_V5_P4_1_wg_n
BPLGUInfoCustomAppSrcP_MT6582_S00_MOLY_WR8_W1315_M D_WG_MP_V5_P22_1_wg_n

All seem to be for the 6582 SoC. But can they be used on ALL 6582 devices as NVRAM database or is this device specific?