Success again! But first of all, thanks to gilles_polysoft and dosdude1 for discovering and sharing this upgrade possibility! Great work. For my rMBP 2013 13" (A1502) I replaced my Apple SSD about 2 weeks ago with a ADATA SX8200 PRO 1TB and disabled (deep)sleep. Ran fine, battery drain was not bad. Still, I was interested in taking it up a notch. I followed Inge83 and his hints (thanks!) and installed a Mattcard with a patched Bootrom - which contains the NVMe drivers of the 2015 Macbook Pro. It is the safest way to get that result, as the Matt card can be removed again if faulty.
I patched the Bootrom myself using the ROM tool of dosdude1 and UEFItool (do not use the A54 version, use 0.26.0). Then I asked cmizapper.nl if he would flash this file on the matt card before sending it out, which he agreed to do (thanks!). Today I installed it, takes only 3 minutes. Restored the defaults of energy management (hibernate 3 and so on) - no sleep issues so far. I will write a short guide on how to patch the bootrom later. For noobs, here is my summary of upgrading options.
Upgrading 2013/2014 Macbook Pro SSD to M.2 NVMe Summary
[doublepost=1548093258][/doublepost]Guide for getting a patched bootrom:
Use Rom Tool (
ROMTool.zip password rom) and dump your ROM to a file. My chip could not be clearly identified by Rom Tool, I simply chose the suggested one. Get OS X Update 10.14.1 to extract the latest Bootrom and its NVMe driver from the Macbook Pro 2015 (Macbook 12,1) - 10.14.2 does not contain a Firmware update, so use 10.14.1. Your current Bootrom must match the version number of the Firmware update!
Use Unarchiver and/or Finder's Show Package Contents, until you get the MBP121.fd file. Open it in UEFItool. I got 2 parseVolume messages - ignore. Search "Text" "not unicode" "case sensitive" for "NVMe", double-click on the "ASCII text "NVME" found". Save the entire branch (51116915-....) by right-click and "extract as is". Close this MBP121.fd file, open your Rom dump from above. Ignore the 2 parseVolume messages about unknown file system. Now you need to insert the saved branch there. Look for "NVMe" again (using options as above), then replace the entire branch (51116915-...) using "replace as is". The result is your patched Bootrom.
Be aware of the following:
This Bootrom file contains your serial number - and maybe also your EFI-password (at least not in plain characters). Understand that before you send it to a third party.
Alternatively, you can flash it yourself - not with Rom Tool, this does not work (signature missing). You could use a SOIC8 clip and a Raspberry Pi to flash the chip on the Matt Card.