The only time it wouldn't be is if the wood is overly dry. And then Teak looks like it wears faster than the rubber caulking. I think that's one reason a teak deck is a sure footed surface.

I expect to end up with a flat finished surface after sanding the dry caulking and Ipe.

I read another thing on the web: Ipe is fire proof. I was putting some cut offs of kindling into a bag to give away. I put the Ipe in the bag and remembered that 'fact', and pulled it back out. Took the 1/8" thick strip of cut off outside and put a torch to it.

Burns great! Gives off a thick black smoke like it has diesel in it. Make a hell of a torch.