Looking good up in here Trich!
Just my 2 pennies here?
Best way to preserve a particular pheno would be cloning, without a doubt! Since that's an identical carbon copy ? Next best would be S1, as you'd be 'selfing' it... Or F2 to a similar pheno, carrying your desired traits, if possible..or F1 crosses, but you'll likely have to hunt/search further/harder to find it again (if at all) since you just introduced a whole new set of genes to the mix. But playing with genetics is/can be a roll of the dice so to speak.
To answer your question to 'would it make sense to grow out a bunch of clones and reverse one for S1s'... I say yes, but also no, lol... But, let me explain... Being a bag seed, you're rolling the dice. And, especially, not knowing anything about the genetics/parentage, you're really rolling the dice on that one. Could be a major hit in the beans or it could be a total miss... Really only one way to find out in this scenario.
She does look great from here! Does she check the boxes you're particularly looking for in a plant? In my opinion, and if you feel she's special enough to you, I'd say go for it...give it a go!! Whether it's a hit or miss, and/or you're down for the hunt, I feel that no matter the outcome... Even if disappointed at times or with some outcomes... it'll all be worth it in the experience alone imho???