I once made a simple vacuum chamber to assist in the release of any bubbles. A large glass pickle jar with screw on lid allowed me to place mix in a mixing jar into the larger jar, place lid on (didn;t need to use a rubber seal) and I use a hand pump to remove air through hole in lid (had glued a washer onto lid to strengthen) with a small o ring around screw in bit of hand pump.You can use a bike pump but you need to fiddle with the valve as they are designed to be positive pressure devices. It wasn't high tech but it worked. Cost me next to nothing.
I found that most bubbles are introduced during the mixing if using a 2 part system and can be greatly reduced by warming the mix (hair dryer) and then eliminated entirely using the vacuum chamber. Some rod builders even flame off their final finish but I have never had to do this.
I agree that thinning is a good solution depending on the brand of coating being used. Differing schools of thought on numbers of coats but I have done up to three on some rods with a lot of threadwork. It also depends on whether you are also using a sealer on threadwork which can also contribute to bubbles on bindings and decorative wraps as the bubbles release after coating and can be a pain with some threads.
Being scrupulously clean re dust is also needed to get a perfect finish but your rod is immaculate in this regard. Hope the above is of interest.
There three types of people, those who watch things happen, those who let things happen and those who make things happen.