I am just going to throw this out for discussion
IMO MTB racing might not be the best use of time and money for someone who wants to get better at cross. Some concerns might be false confidence i.e. there is a lot of stuff that is easy on an mtb that I would not consider on a cross bike. Also, lack of overlap in skill sets; for instance, when was the last time you did a series of 180deg off camber turns on wet grass with barriers between them while on your MTB?
I think those who want to get better at technical cross riding, most of us, should do more technical cross riding. Buy some flags, make some barriers, and put together some courses that will challenge you. I had considered getting back to MTBing, but I think I am just going to take most of August and set up some stuff that simulates challenges in cyclocross rather than spending time and money doing racing/riding that will not necessarily transfer well to cross.
I have not shut the door on doing some MTBing, so I would be interested in peoples dissenting opinions, but I think the old adage applies in this situation; if you want to be a writer, write.