You don’t optimise gearing by looking at the “top end” (outside of genuine sprint cycling events but then we’re talking 65x15 fixed set ups…) You need to optimise for the speed/cadences you spend most of your time in.
The 1 hour into a headwind at 150w, the 1 hour with a tailwind at 150w, the slight uphill drag, the poor road surface etc. the bit of the race where you’re feeling crap, the bit where you’re feeling better all of those will change your speed for the same effort - and a triathlon you want to keep the effort the same, which means you will almost certainly need to keep your cadence within a narrow range, If you want to optimally ride at 40x11.5 then you either have to work harder (keeping 40x11 at your preferred cadence) or ride slower (keeping 40x12 at your preferred cadece)
To avoi that, you care about having a small difference in ratios in the part you’re riding most of the time - not the almost 10% jump in ratios of 11 to 12 - they’re not important, it’s what you have in the 14/15/16/17, where the jumps are small that you optimise the size of the large ring for, is that 48 or 54, or somewhere in between. It will depend on course (a flat, hot, windswept course on perfect roads will be different to cold lumpy rough english roads course)
Of course you need a low enough gear to get up any hill without the same problem, and with long hills it’s possibly even more important, although hills are generally not in triathlons, but it does get hard, still you want low enough gears to get up them easily again in close ratios if you can - the difference in ratio between your 25/28/32 are over 10% too, so you don’t really want to be in it - however realistically on lots of hills you will be 'cos 34x28 may well be needed on steep hills.
The place to worry least about gears is if you have an 11 or 12 - if you’re going the speeds enough where you can use those gears, you’re probably better off resting anyway (the return on more watts at that speed is very low, save your energy for the run)
As you note, running too big a difference between large and small front rings is impossible, so you need to compromise, or get a triple, but don’t think only of the extremes in the compromise.
52x34 is doable on many bikes, Maryka rode 52x34 12/30 in a hill climb and used both extremes, and had in fact tested the bike with 12/32 but didn’t need to race it due to it being a tailwind on the hill, but it is outside the spec, so it is a bit suck it and see as @Jgav says.