>>2998293call labs that have been in business a while, a lot of them still kept it because it was fuck all expensive back in the day. It's intended use was making negs from slides so you could have the saturation and color density of slide film but print on the much better color neg papers.
Yeah, I'm piss at developing but when I first doing it, I did it with trays. put a piece of glass from a cheap frame in the bottom of your tray, it helps.
Somewhere on LFPF theres a guy who said that you can't do double sided in Jobos, so I dont know about that. I also have never heard about using a filter over a meter like that.