Keh, getting more than 0.1 raditz from that fat slug's "power unlock" really is a cheat.
This gaiden's writing kind of fails in that it makes the same mistake a lot of fans do - they take the story (which is nonsense, even by its own rules) literally when that isn't how that world works. DBZ isn't xenosupremacist, it's typical protagonist = master race shonen stuff. The way to acquire more power isn't training or secret life hacks, it's by getting the most screen time, defeating the most raid bosses, and novelty.
So the correct route to take is to make sure to annihilate all of Goku's enemies before he can even show up, make sure to kill Vegeta before that zenkai bullshit can be established as canon, and for the love of god get Bulma and her dad working on that gravity chamber and some kinda human body modification technology to further raise your level cap pronto. A protagonist vacuum must be filled, and as the only guy accomplishing anything, you'd be Super Wolf King Yamcha in no time flat.
A couple obvious examples of how DBZ does not operate on any principle of logic:
* That time Goku had trouble with a 10x gravity field. Aka, walking around with an extra 1350 pounds on his back. This isn't anything special compared to stuff he's done and adapted to before - it only works because it's new and novel, because it
entertains the audience. Just like how swimming away from sharks or playing keep away with a cat shouldn't have any special results.
* There were millions of Saiyans before Goku, all with the cheaty power of zenki (retroactively established, and then ret-conned away) and the potential of becoming "super". Most of them living lives of constant warfare against space aliens, and not one of them became anything special. Then suddenly, after hundreds of thousands of years, every single Saiyan born on earth surpasses this "legendary" feat that their entire race could not reach. This goes beyond winning the lottery a half a dozen times, it can not possibly happen by chance or effort - only by the narrative powers of the world they're living in.
Screen time + success + popularity = power.
Shonen battle series are very similar to isekai in that manner - the person who gets the most EXP (screentime, victories) becomes the strongest so they hog the most EXP.