ADVISORY

If the Beluga XL, when you make sharp banks,
- doesn't respond to your inputs
- has its main landing gear starting to pop out of the aircraft
- starts having said main landing gear braking (smoke and noise are visible)
and/or
- pitches up and climbs rapidly, making it hard to fly properly,
the bottom of the A320 fuselage may be stuck inside the landing gear bay, hindering the retracted landing gear.
To solve this, you can retract the gear on the ground, and then spawn the A320 fuselage.
Also, make sure you move the Beluga forward (and maybe set a custom location for future flights) before you spawn your A320 fuselage.
Hope I managed to help you!

So, I downloaded ReignSupreme's Airbus Beluga XL (and increased its upvotes to precisely 150) and thought it'd be great to actually transport aircraft parts in this majestic aircraft. This was the result.

This A320-200 fuselage is painted in anti-fouling paint and is ready to be transported for final assembly. As always, this aircraft livery is made to be as accurate as possible, with a comparison between the real-life example and my livery above.

You can use it to satisfy your desire for transporting oversized cargo in the one and only Airbus Beluga (it may fit into a Boeing Dreamlifter but I haven't tried that out)! Maybe you could even use it as a ground target if your fingers feel itchy.

I kinda already said where I got the various things from but I'll list them anyway:

Credits

Fuselage: GalacticaAsia's A320 EasyJet
Reference Airbus Beluga: ReignSupreme's Airbus Beluga