Why not just leave it at the large size all of the time, and just set the “forward time” to a small number, like 100ms?
The forward size and forward time work together to trigger the forward: if either condition is hit, it forwards. The forward size, though, also affects how data is loaded from the cache, and therefore can have an impact on catching up, as you’ve noticed. However, as long as the “time” portion is small enough to cause data to be forwarded constantly in the normal state, I don’t see a problem with with “size” portion be as large as you’d ever want it to be.
Regards,