If a shop offers Late Surrender, is it standard to offer LS after Split as well? I would think the answer is NO.
Most players don't use Surr. So, they certainly won't think about using LS after Split. I got an opportunity to use it, and asked if I could surrender. She was caught off guard, thought about it and said Yes. But I don't think the House intended for this rule. I believe Surr is supposed to be used exclusively on the original two cards.
In practice, there are only a few combinations that this could reasonably come into play:
* split 8's vs 10/9. Catch a 7, 15 vs 10/9 may be a viable Surr.
* split 9's vs 9. Catch a 6/7. 15/16 vs 9 may be a viable Surr.