If you are a Mid South competitor you should be allowed to compete in the regional event whether you are doing the series or not... thats like saying your not doing the national series, so you can have a go, but your be in separate finals...
Its a Mid south regional event which is open to racers that choose to race in the Mid South region. As per the BRCA rules, you are not allowed to enter more than one regional championship. Should Joe Blogs and others want to race in Mid South this year and not one more local to them, that is their choice. Should that happen then of course it does mean they have eliminated themselves from entering other regions events.
Thats why regions were never set up to where you live or what club your a member off, but by which regional champs you choose.
And if a club decides to run an open class at said regional event, then great, more the merrier, but it should be a separate class, just like 2wd or 4wd.