After a fun day out my clutch was spot on all day, tiny bit of drag when cold so new steel plates seem to work.

To find neutral I find it easier to select 2nd and tap it down just a smidge.

The US importer recommends Silkolene Light Gear Oil: http://www.motorhelmets.com/htm-enginepart...-light-gear.htm

It works fine in my 4RT. Mine's a 2007 though and was promoted as having clutch upgrades so I'm not sure whether it reduces drag in earlier models.

I've been down the same road with my 315.

I now have CR250 plates in it and I use ATF.

This seems to have improved the drag substantially (once warm), but I'm now struggling with the lack of "gradual-ness" for want of a better word. My clutch is now more of an on/off switch. Nothing happens in the first 70% of the clutch lever movement, then it's on/off at about 75%.

Any advice on what could be changed, fixed, adjusted to give a more gradual engage/dis-engage ?

I had clutch drag when i first got my bike as well,

I changed the plates (stayed with stock) and replaced the oil to silkolene. I think the thing that made the biggest difference though was changing and bleeding the dot4. It did it all at the same time though so not sure. I can now start my bike in any gear and it'll tick over fine. Every couple of months it'll start to come back but a quick bleed sorts it out everytime. The best way i've found of bleeding is to back bleed. Take the top of your reservoir and tape a bowl under it (to catch the run off) fill a syringe with dot4 and push it in from the bleed nut (at the clutch) It'll push all the air up out of the top which is the way it wants to go. Its also a good way to change the oil, just keep pushing till the stuff coming out at the top is clean. Can make a bit of a mess but i find it a lot easier.

All of the foregoing could cure clutch drag but I have found in just about every trials bike I have ever bought that the biggest cause is a 'grooved' or 'ridged' clutch basket where the friction plates dig into the aluminium. If you have a half decent oil (ATF is as good as ny I have found or Castrol SLX) and your clutch is adjusted properly, I would look to the wear on the edges of the clutch basket before spending a lot of money replacing the plates. Most clutched drag when the oil is cold.