Oil System Upgrade query

I have the factory breather/oil interceptor and oil system upgrade kits to fit to my 2014 Sport.
So far have fitted the non return valve (line to the oil cooler), filter (line to oil pump) and the gauze screen in the scavenge from the sump.
Next was to be the sleeve and spring/ball non return (?) thingy in the oil pump but the instructions note that the breather mods should be finished first.
Anyone know whether there is a technical reason for this or is it just a convenience thing?
I haven't yet decided how much of the factory breather/oil interceptor stuff i will fit, hence the question.

I would fit all of it. If you don't want to press the one way valve into the pump you can purchase the latest revision oil pump from Norton and it will be already installed.(this is the best way because you get a better tighter oil pump) Don't forget to clean out the press shavings after fitting the valve into the pump. You probably already looked back into the archives and saw the posts with pictures about this step.

Thanks Tony, i might look into the new pump at some point but it has taken 9 months of persistence to compile the small pile of parts i currently have. Not sure i want to go there again just at the moment.
I'll have a go at the pressing etc.

4600 miles since my mast oil change. Level is still perfect...oil is still unusually clean from engine. Upgtade at about 2200 miles. Tranny needs to be topped off on occasion with a couple ounces per 1k miles, dirty with a silvery sheen. Original air filter still clean, teaspoon of oil in airbox.

That makes good reading, thanks.