I've been flying one for 26 years and it's most certainly NO brake for t/o or landing. If the rudder runs out of authority in a crosswind, either at the start of t/o run or (more likely) at end of landing roll, just reach down with your left hand and apply a bit of brake (the rudder will already be hard over, so only the approriate main gear brake will be applied).
Landing with brake already applied limits rudder movement and runs the risk of locking a wheel and groundlooping when you run out of that limited rudder authority. Much better to have all the rudder movement available, then only apply the brake if it become neccessary so to do.
It all works very well - you just need to curl your little finger around the brake lever as you slow, and gently pull as required contolling direction by how much 'pull' you apply - it don't take much effort.
SSD