This is why a triple still makes a lot of sense but then of course you run into issues with your brifters. My bikes are all older than yours and I run triples on a lot of them. I'm getting ready to do the Dairyland Dare in August and I'm taking my granny with me,
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https://www.dairylanddare.com
Have you thought about a 11-36 in the rear? That will probably mean a new RD and perhaps a chain but it's cheaper than a new crank.
That said, I think your plan of going with a 46/30 makes a heck of a lot of sense for the kind of riding you do. The sugino OX601D or OX 801d would be near the top of my list for a modern bike but it is expensive,
Sugino OX601D Cranks Arms w/BB Cups
Alternatively as someone else pointed out you could check out eBay; there are Japanese online vendors you can buy this from as well which will be could save you some coin.
https://alexscycle.com/products/sugi...act-plus-crank
https://alexscycle.com/products/sugi...601d-with-bb-1