I recommend a hardening fixer.
I'm cheap like borscht. I don't buy anything I don't have to. I paid 15 bucks for my camera. I shoot arista.edu bulk rolled at 21 bucks a roll, I use pool chemicals to make developer and fixer, I use clothespins with pennies glued to them for hanging my film and I hang it two to a clothes hanger.
It's hard to get cheaper than a Univ. student, me and my GF get excited over name brand Kraft Dinner.
I got alot more crap stuck to my film while I hung it up to dry in my bathroom, and more sediment stuck on it from the rinse water, and just alot more garbage in the emulsion in general.
I've had to go to the five dollar gallon powder envelope from the store. It's just the way it is. No matter how cheap I am, I still can't justify false economy.
For these reasons I recommend a hardening fixer.
What I really need is to find a good recipe for a hardener agent to add to plain old pool chemical supply sodium thio to make it hardening fixer.
Not sure why you want to harden roll film. Possibly sheet developed by hand, but not roll on a reel. No need to handle until washed, then if it gets scratched, I'd look at your handling. I've never used a hardener and I don't think I've ever experienced scratching except with admittedly grossly mishandled product.
Putting hardener in a fixer sounds great, one less step. In reality, it doesn't make sense, at least to me. The hardeners in common usage require a significantly acid environment. Your "simple fixer" now becomes a balancing act of available thiosulfate molecules and the chemistry of the hardener. Then, if you use fiber base paper, the wash times increase and it's harder to get all of they hypo out.
If I were to want to harden an emulsion I would use a separate post-fix bath. Much easier to keep, maintain, or keep for optional use.
Standard acid fixers require, for instance, 15 grams potassium alum and 45cc of 28% acetic acid. So, now you need to buy acetic acid, too. If you add 240 grams hypo and 15 grams sodium sulfite, you have Ansco 201. Use undiluted.