With 50m gold medals in all four strokes on offer at an Olympics for the first time at the 2028 Los Angeles Games, the Australian will look to earn selection in the butterfly sprint at national trials before bidding for medals at the July 23 to August 2 Commonwealth Games in Glasgow.
His teammates' hopes that he might add 100m freestyle to his repertoire and help Australia win relay titles have been dashed, though, with the 31-year-old adamant it would be too difficult to juggle.
McEvoy, whose innovative training methods have been copied by rivals, says the same stripped-back regime that has brought him Olympic and world titles is equally applicable for the butterfly splash-and-dash.
"It's one to one. The only difference is technique but everything else really comes under the same banner," he told Reuters on Wednesday.
"So I wouldn't have to change my training at all. It would just be exposing myself to trying to unlock the right butterfly technique."
McEvoy swam the 50m butterfly virtually on a whim at the 2024 Doha world championships and took a surprise bronze in the event.
He shelved the stroke to focus on winning 50m freestyle gold at the Paris Olympics and says he is still very early in the journey to optimise his performance.
He swam a personal best of 23.05 seconds in the 50m butterfly at the China Open meet in March, two days after his 50m freestyle world record (20.88).
"So there is crossover there, and I think a little bit of scope to -- if I trained it properly -- move the needle a little bit more," he said.
McEvoy is wary of putting too much time into butterfly as he focuses on raising the bar in the freestyle.
He noted the last five metres of his world-record swim in China were slower than his world championship swim at Fukuoka in 2023.
"So right off the bat, there's 0.12 (seconds) in the last five metres alone," he said.
"There's a little bit of low-hanging fruit left to take, and maybe cut a 10th (of a second) here and there."
If McEvoy sounds confident it is only because he has the data to back it up, and a love for the maths and physics that underpin his pursuit of perfection.
He is an open book about his training regime which involves fewer laps, more weights and coaching the nervous system to transfer gym-built strength into power in the water.
People have called him an "idiot" for being so open-source about his formula for success, he said, but he regards it as his contribution to improving the sport through innovation.
"You see time and time again, people burning out, leaving the sport, hating it," he added.
"And so it was an opportunity to not only allow people to have another path to get to where they wanted to go, but they can still continue with the sport and not hate it."
Leaving that legacy sounds just as important to McEvoy as his four Olympic and 10 world championships medals, a haul that would be the envy of most swimmers but one that has generated little commercial reward.
Even after his world record McEvoy is not signed with any major sponsor, and he said the corporate apathy had taken him a bit by surprise.
Ironically, doped-up swimmers at the upcoming Enhanced Games in Las Vegas will have the chance to earn prize money that clean athletes like McEvoy can only dream of.
Focused on winning Olympic and world titles, McEvoy said he had never seriously considered signing up for Enhanced but cast no judgement on those who had.
"The access to that form of finance is literally one message away. And knowing that has been really tough to deal with (but) wasn't something I'd ever act on," he said.