When surrender is offered on a six deck european style face up game, how do I classify it ?

I assume if its against any dealer card is considered early surrender.

What if they let you surrender against all cards execpt the Ace ? . This must be better that late surrender, because you can still get some money back if the dealer gets a back door BJ but worse that early surrender.

So what sort of advanatge does it give you off the top off the shoe ?
And
What basic statadgy and Hi-Lo indexs do I use ?
I assume the ones as early surrender but ignore the vs Ace bits.

Thanks.