Not sure the BT3K will output enough volume for the X2. Honestly would've just got a Mixamp 5.8 for this. A little hissy, but no latency.
I had similar concern, but it worked out. The BTR3K volume goes up to 32 in the app. At volume 28-30, it's more than loud enough for gaming, and I don't like quiet. Anything higher volume is almost uncomfortably loud. For music priority, I would probably step up to the BTR5 for extra headroom, just from the few tracks I listened to over the weekend. BTR3K is pretty sweet for gaming though. I connected the BT transmitter to the output of my Magni 3/Loki combo. With the Loki, I can still adjust EQ on the fly. I tried bypassing the Magni/Loki by connecting the 3.5mm BT transmitter directly to the output of the Turtle Beach TAC, but even with Fiio EQ app the BTR3K it was too lean sounding with that config. BT transmitter and BTR3K are both Apt-X LL capable, and I don't notice any audio lag.
Now I have a setup I can use wireless or wired if needed, and still get full chatmix control from the TB TAC and not be tethered. I'm pleased with it.
I actually own two Mixamp 5.8s. One I use in the living room for late night viewing. The other I still have reserved for PS4 use, but I got tired of having the cable between mixamp and headphone. The Mixamp 5.8 is one of the most versatile pieces of audio gear I've purchased. I really wish Astro would have continued updating the product. Something similar in a much smaller form factor would have been an ideal solution vs. BT for sure. Same with the Soundblaster E5. -Great product with excellent app support and great sound, but I wanted something with a small form factor that I could attach to my headphones and not be restricted to fiddling with wires.
This is the BT transmitter I purchased: https://www.amazon.com/gp/product/B07WP3DGPB/ref=ppx_yo_dt_b_asin_image_o01_s00?ie=UTF8&psc=1
The Mixamp 5.8 I can get about 30ft from and it starts cutting out. With the BT transmitter & BTR3K I can walk to all corners of the house without it cutting out.