Heatsingk only:
Heatsink + fan (select 5v):
Please note you have to replace the plug of the fan with PH 2.0MM 3pin.
I arranged to fit the board in a BPI-R3 plastic case manually modded and adapted a plastic grid on the topin order to have air flow. Unfortunately I had to disconnect the fan because not possible to control and I do not want to keep it always on. At the moment the temp with the passive heat sink is around 57°. I htink acceptable.
Oh so the mounting holes are exactly the same as south/north bridge heatsink? That's great, I will try to get a bigger one first.
I found a “starter case” with fansink for R4 on aliexpress:
Case with and without fan:
https://de.aliexpress.com/item/1005006541585546.html
Fansink alone:
https://de.aliexpress.com/item/1005006544838058.html
Cons:
The acrylic case has no holes for wifi antennas or 5G cellular modem (DIY).
The thermal pads beneath the fansink (DDR4 and eMMC) are looking thick.
Pros:
3 pin PWM fan matching with R4
fansink will be be easily installed via push pins
price okay?
Original post:
I'm also interestet in Fibocom FM350GL. But banana pi prefers Quectel RM520N.
I did not look for the pinning of FM350GL. Is there a 100% match for R4?
If the offical firmware snapshot supports the FM350GL out of the box, then please write back!
If someone has tried RM255C-GL, then please also write back too. For me it is very attractive, because of less power consumption!
I bought an acrylic case for BPI-R3 for my BPI-R4 and the fan (it works only on 2 pins as per documentation).
For bottom I used longer stand-offs to fit NVMe and Wifi cards. I dont use all back sides per now. Maybe if it will come I will organize something better 
Confirm some fan pwm doesnt work... so my fan is working all the time
I was working on setup FM350GL on my BPI-R4 and now it is operational.
You are a maker 
! I have done the same for R3 by using R2 acrylic case.
There is also a discussion at banana pi forum:
Looks like fan-PWM will need a bit time!
For me the most important topic is this:
Hi, the Intel be200 is working fine with the adapter? Recently I bought a Intel card with the adapter and compile image with config options:
CONFIG_PACKAGE_kmod-iwlwifi=y
CONFIG_PACKAGE_iwlwifi-firmware-be200=y
And it does not work on my side. Have you done something more?
BE200 is already supported? I thought not yet
@danpawlik & @DroZDi I have not been able to get Intel BE200 based m.2 cards to work on AMD based platforms. It looks like they only work in conjunction with Intel based processors/chipsets. I assume the same problem also occurs with ARM based SOCs.
From my point of view it looks like the recent hardware generation is not fully PCIe compliant - compared to previous generation(s) connector has changed also to something CNVi-like (E/A key to E only - see picture).
they work fine in Nvidia Jetson Nanos
I've tested Intel AX210 and it works fine with MediaTek's FiLogic SoC.
Very slick can you share which antennas are you using?
I'm aware that AX210 does work with many plaforms.
The question opened here is about the new BE200 module 
For a modem FM350GL antennas provided with the module - like for laptop usage. But as in my location 5G coverage is on the edge Im thinking to to get something new.
For internal Wifi (MT7922) I got something on aliexpess but I didnt make many tests by now as to be honnest I made my router running 6 days ago it was more then 1 month wating for OpenWrt 
Have you done something more than adding
CONFIG_PACKAGE_kmod-iwlwifi=y
CONFIG_PACKAGE_iwlwifi-firmware-be200=y
Into the .config file to make it work on the Nvidia Jetson device?