I'm glad you found it helpful - happy to share some experience!

In regards to 100% vs blends, I think it really depends and varies on the brand and use case. The durability difference might perhaps be slightly overstated for most casual wearers, but I also am not super hard on my clothes in general.

If you're serious about merino, start checking out the gsm of the fabric, and the weight/oz. This should give you an idea of how dense the material actually is - there are definitely some 100% merino products out there that are very low quality compared to blends. Construction of the actual fibers can also radically impact how well an item performs. Things like drape and fit can also affect how well merino does its job.

Above all, don't consider "merino" blends that have less than 50-60% merino - the clothing won't have the performance one expects from merino.

E: forgot to mention that anything Outlier makes is truly Onebag / BIFL appropriate. I haven't tried their UFT, but their Daybreak merino t is my current fav t-shirt. I mostly gauge merino performance on how it handles sweat, smell and repeated wearings before washing. In those regards, I don't think I've noticed a difference between blends and Outlier's stuff. Not to mention that their merino is better / on par with W&P and Duckworth's 100% stuff.