Yaesu FTX1 Bluetooth Cover
If you buy the Bluetooth Adaptor BU-6 for The Yaesu FTx1 or Optima then it comes with a deeper cover to allow for the fitting of the Bluetooth module. However, the BU5 module is the same but without the extra cover.
If you have a BU5 that you could use then this is a 3D Print STL file for a cover that fits.
I printed this upright with supports on a Bambu Labs X1 Carbon