E-series (E6x20 and XT3) and Bluetooth 380

Hi,

I am still using a couple of 3rd generation E-series Latitudes (SandyBridge-based E6320 and XT3), both on warranty. Officially they only shipped with Dell Wireless Bluetooth 375 (Broadcom-made Bluetooth 3.0 w/o HighSpeed aka BCM2070), but recently I have noticed the Bluetooth 380 driver[1] which claimed to support above models. Physically modules and cables look the same, so I gave it a try. I went to Ebay and bought a couple of these Bluetooth 4.0 + LE adapters[2,3] (03YX8R aka BCM20702). Unfortunately, adapters didn't work neither in BIOS/ePSA nor in Windows/Linux. They seem to be in order because laptops hang for 3-4 seconds more than usual when booting and both OSes discover unknown USB device (no VID/PID). (The seller sent another batch with same results.) I have never heard of Dell whitelisting (or blacklisting) wireless cards but it looks exactly like blocking on a hardware level (Broadcom ROM fails to load and USB devices are left uninitialized).

TL;DR A couple of questions.

First, did anyone try to upgrade 3rd generation E-series to Bluetooth 4.0? Did it work?

Second, could it be that modules are operating in some strange mode like HID proxy or something? Just like it was with Bluetooth 355(?) (don't remember model) when you had to switch mode depending on what you are booting -- Vista or XP/Linux.

Third, did anyone hear about Dell whitelisting hardware? Could it be that Bluetooth 4.0 + LE ROM is (at least) partially bundled with system's BIOS (just like Intel RST), so it won't initialize properly in unsupported hardware configurations?

Fourth, could anyone from Dell, please, comment on this?

Thanks a lot in advance.

[1] Driver Details | Dell US
[2] Dell Wireless 380 Bluetooth 4 0 Module CN 03Y8R Latitude E6230 E6330 E6430 E5510 | eBay
[3] Brand New Dell Alienware Truemobile 380 3YX8R Bluetooth 4 0 Card Fast Shipping | eBay