I also think 1 oz for testing is good. I think Soapmaker145's testing process is different than a lot of us, in that a lot of FO samples are ordered and tested, several to a small batch of soap. I will tend to order 1 or 2 ounces of a few FOs that sound interesting when I am ordering other supplies. Then I make a 1 lb or a regular sized batch to try it out. If I like it, I'll order a larger amount and if not, I can find someone to give it to.
I haven't tried too many of the MO fragrances, but FWIW I'll share my thoughts. I'm not huge into florals, but I really like Elderflower. It's a green, fresh floral - not too perfumy - and it behaved very well for me. It reminds me of Linden. Snow Witch and Vanilla Milk are two of my very favorites, and happily it seems you already have that covered. Arabian Nights and Velvet Peppercorn are both very nice, but I use both of them as blenders rather than stand alone FOs. I blended the Peppercorn with Anise EO and got a weird pink discoloration in my TD parts. The other blend I used it in was a light brown - I think from a moderately discoloring FO and I used a pretty small amount of Peppercorn in that blend. So I don't know if I had a fluke with the pink discoloration or if it would happen again. Two I've tried and wouldn't reorder are Spanish Fly and Golden Embargo. I think the Spanish Fly was just too powdery/musky for me and I am, I think, one of the rare people who just don't like heavy amber. A little amber in a blend is nice, but that one was just way to much for me. I also tried Lavender Chamomile - again nice, but not so different from others. I've been curious to try Deviant, Hedonic Tonic and Cucumber Lavender, but what I don't know I won't miss.
ETA: Soapmaker, I do appreciate your testing process, and have taken your advice on more than one occasion.