Lucky sevens rule in South Korea

Hi, First post here.

I'm currently studying in South Korea and they have a special rule for Blackjack at the Lucky Seven Casino in where they will pay 3 to 2 (like getting a blackjack) if you get 21 by getting three 7 cards.

I was wondering how this special rule changes my play if I get a Pair of 7s and also how much of an extra edge this would give me.
Basic Strategy says Split against 2-7 and Hit against 8 or higher.

I think that you still follow Basic strategy since against 2-7 you want to split to put more money on the table (since dealer is more likely to bust, if he has 2-6), try to get a push against a 7 and also because a total of 14 means you have a high chance of busting also.
Is there actually a time I shouldn't follow Basic strategy?

This rule is still going to to give you a higher edge, since against 8 or higher Basic strategy says to hit anyway. So how do I calculate this edge?
The probability of getting a 7 is lower already with 2 sevens on the table. They play with 6 decks I believe in this casino.

Thanks

Chris

google (which led to a post on this site) reveals that this changes HE by +.02%