I'm no expert but I've had some experience with swim bladder issues. So I'll share what I've heard as well as my personal experiences in the hopes that one or both will help.
From my understanding of what I've heard, swim bladder issues can occur for several reasons. One is when constipation in a fish gets so bad that the unmoved matter and swelling/inflammation of intestines creates pressure on the swim bladder. In other instances it a result of disease/infection causing inflammation which again presses on the bladder. In others still it's the body shape of said fish that causes the organs to press against the bladder. This pressure makes the fish unable to control their swim bladder which makes them therefore unable to control their buoyancy. It can cause the fish to take on ahead down, tail up or vice versa head up tail down position in the water. It can also cause them to flip or sink.
I have no personal experience with Breidorhi but have kept similar fish such as Synspila, Regani, Hartwegi, Zonatus and Argentea. While they are omnivores from my understanding their diet should be more biased toward plant/vegetable matter. So pellets high in protein can be a potential causes for a swim bladder issue. Again while I have no experience many say that feeding peas could help alleviate the problem and making sure their diet consistently includes a fair amount of plant/vegetable matter should prevent any relapse.
Now for my personal experience. I've had several fish with swim bladder issues. I had a Green Terror and several Flowerhorns get it from white poop syndrome my Zebrina and Brachiatus catfish from overeating and Blood Parrot due to a birth defect caused by body shape. In the instances where I could cure it Epsom salts worked for me. The Blood parrot which is still alive today was the only one I couldn't cure. Adding it to water and pellets gave the quickest responses but the catfish was sensitive to the Epsom being added to the water, becoming obviously distressed. So my suggestion would be to only add it to the food by soaking it in a bath of Epsom salts.
Also not to disagree with Charney who is a very knowledgeable hobbyist but in my experience feeding sinking pellets doesn't help prevent or cure the issue. However your suggestion of soaking pellets first would help decrease the likely hood of a swim bladder issue developing. Reason being fish gulp down the dry pellets which then expand in their stomach as they absorb water causing issues such as constipation. Soaking the pellet first should prevent that from occurring. Again that's been my experience their maybe people more knowledgeable who might totally disagree.