Not sure in either case. Remember we are talking about the 1940's and 50's.
The cross hatching on the mold design itself would have stopped slipping.
I wonder if they had more than one mold available at the same time and the customer had the choice. The earliest TRK's appear to have zero cross hatching at all.

Thinking about it, most distributors back then offered a choice of molds and they were a mix of cross hatched and smooth.