South Africa joining the 6N is a solution looking for a problem, and failing to find one; and doesn't really do anyone any good.
The problem with the 6N, as has been mentioned repeatedly, is that it's a closed shop; but the solution is tough to find.
6 is plenty of teams already, and I don't think the tounie could cope with expanding to 8, or any odd number.
So promotion/relegation is the only answer - but bring the question of "but how"
For home & away fixtures to even out, it needs to be every 2 years; but even then, every 4 would be better to allow the promoted team a chance to get their feet under the table - which would effectively kill the relegated team down to, at best, the level Georgia currently occupy - comfortably better than every else, but nowhere near good enough to challenge the top tier.
So it kinda has to be a play-off between the bottom of the 6N and the top of the ENC - to be fair, it needs to be home and away; or at least, at a neutral venue. Which means you need to find space in the calendar. That space needs to be found for every team in the 6N in case they suffer a terrible run and end up last. That space simply doesn't exist in an already congested fixture.
It's also pointless aiming for a top-down approach, greater investment and encouragement is needed at the age-grade and club level of the lower tiers in Europe. Which is tough as hell, and beyond the remit of the 6N comittee.
I think the easiest, viable change might be to expansion of the U20s 6N and allow promotion within the EPRC (is the 3rd tier of that even running still?)