TS-262 memory upgrade?

[csabius]

Hello, fellow NAS enthusiasts!

I recently bought a QNAP TS-262 and started to add components to it (HDD, M2 SSDs for now).
Ever since I have opened the case I have seen that contrary to most product presentation videos (including the one on nascompares yt channel), it doesn't have the memory soldered on the MB, but it has two SODIMM slots! The first one has a pre-seated 4Gb module, with a seal so we don't mess around and lose the warranty, the other one is empty.
Now, this triggered a huge itch for me to try and add - at least - another 4Gb module to the empty slot. To be sure, I have asked QNAP tech support, who keeps saying that the specs state, that on this model the memory cannot be upgraded. On the other hand, looking at hardware info from QTS i see the following:
   
   
Tech support also told me about some conflicts (?) I may be experiencing if I add another SODIMM, although they specifically said that I will not lose warranty if I add another module...
My questions are: 
1. Any of you seen this, or have experience with TS-264-2G, which has upgradable memory? I have a feeling that I've gotten a TS-264-2G motherboard on my NAS for some reason...
2. Would it be worth it to buy a memory module and install it in the NAS? If yes, which type/manufacturer?

Any comments or thoughts are much appreciated!

Regards,
csab

[ed]

Yes, if there is a free slot, you can upgrade. Their freshly manufactured devices under the same model number will replace existing ones with soldered versions.

[csabius]

Yes, if there is a free slot, you can upgrade. Their freshly manufactured devices under the same model number will replace existing ones with soldered versions.

Hey, Ed, thanks a bunch for reassuring! Is there a special DIMM type I should use? I am looking at a DDR4 DIMM with 2666Mhz speed and CL19. Do you think this one should work?
Regards,
csabius