It was me 'carry a few kts for position error and inefficient flight mode'
It is very true increasing IAS may not be required on some types.
Though I also think it is worth remembering here we are talking about a very mild slip during a wing down approach compared to the full on taildragger express elevator down type approach which Mike might be thinking of.
In all, gusty conditions, plane producing more drag, it might be better to think in terms of more power and watching the IAS with care when doing a forward slip crosswind landing. Certainly I find it needs more power to arrest an increase in descent.
I have to say though that in the Super Cub I've always been advised to carry an extra 5 kts in a full on slip to lose height to compensate for position error. Could be wrong could be right, the instructor is massively experienced with tailwheel so that's what I do.