You already have more touring experience than most people that ask questions on this forum, so you probably already know the answer. But as noted by Happy Feet, there recently was a lengthy thread on a very similar topic.
I have three touring bikes. Two have triples and eight speed cassettes, they are great and the wide range of gearing at 558 percent gives me a wide enough range that I can pedal up the hills and also pedal down the shallow downhills instead of coasting. My third touring bike has a Rohloff which has a range of 526 percent. At times I wished I had more range on that bike for the downhills where I often spin out, but I am unwilling to give up my lower gears to obtain higher ones.
A 1X system with a 11-46 range would have a gear range of 418 percent. I think that is a pretty small range for touring with a loaded bike. My randonneuring (audax) bike range is 504 percent and my road bike is 355 percent, and I never carry more weight on those bikes than a bag of groceries.
If you really are convinced that a range of only 418 percent is adequate, go for it. I would want more.
I avoid the two most cross chained gears for each of my chainrings, thus my derailleur touring bikes with an eight speed cassette only give me 18 usable gears instead of the 24 possible. But still I find 18 is a lot better than 11. And my Rohloff with 14 gears also gives me a few more choices than you would get with a 1X with 11 speed.
Since one of my bikes has a Rohloff, I certainly understand the benefits of a single sequential shifter. But I do some of my touring on the wider range derailleur bikes with a triple instead of the Rohloff because the benefit of more gears and more total range sometimes outweighs the advantage of a single sequential shifter.
Those are the issues I would be thinking about.
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On materials, almost all of my chainrings are aluminum and almost all of my sprockets are steel, so it is hard for me to make a good comparison. Thus, these are only my thoughts, I can't point at a great wealth of experience on materials. On my derailleur touring bikes, the smallest chainring is an aluminum 24T. And I have no perceptible wear on that chainring on either bike, but I use it rarely, only for the steeper hills. That said, I still use that chainring much more than my largest sprockets on my cassette which are only used for the really steep hills. I suspect that if you have some cassette sprockets that are 37 and 46T that are aluminum, you would probably still wear out the smaller steel sprockets on the cassette faster because those smaller sprockets would get much more use. On my eight speed bikes, the 16, 18 and 21T sprockets are shot when it is time to replace a cassette, but the other sprockets are in great shape because 80 percent of the time I am on those three mid-cassette sprockets. You mentioned a 30T aluminum chainring, how much are the replacements at Spa, I suspect that they are reasonable in price. Maybe the 30T replacement is cheap enough to carry a spare on longer tours.
On my triple systems, I have never replaced a chainring due to wear, but go through a lot of chains and some cassettes. I really like the lower price of the eight speed gear. Not sure how you consider finance on replacement of expendible items, but you might consider the prices of the 11 speed chains and cassettes compared to the parts you would have with a triple.