Interesting. In 4 years of use I can't think of an instance where I would have wanted/needed to use a locking one wheel brake. My opinion is that's one place to save some money for sure and leave that option off. Who knows, maybe I'm missing something wonderful that I never knew was available as and added option for I'm sure many added dollars.

My opinion on not getting anything but the turf tires is because, again, after 4 years of using three different Fs I've never needed more traction while mowing up, down, crossways that a more aggresive tread would have helped. Have had NO traction issues on dry land and I feel certain I've attacked/mowed or crossed while going to mow as steep a slope/hillside as anyone with an F. In wet grass, which I have encountered in a couple of low spots after several days of rain, I don't think a more aggresive tread would have helped. I don't do mud mowing, except the one time and I did get stuck with my turf tires and had to be pulled out. More aggresive tires WOULD have helped, I'm almost certain BUT I'll never get back into that low corner where water stands after heavy rains again. It's a far corner that I don't mow, I was pushing some trash into that corner to hide it.

I encourage people to try what's working or probably will work before spending/worrying about what might happen in the future or worried about/change everything for that less than 1% possability at possibly the expense of the other 99% probability.
Most dealers do not keep Fs in stock but if you find one, go try it and if they have a steep hillside , try it there. I've went down extremely steep hills that were dry and never slid or spun while going up them and I wasn't mowing at the time, I'm talking hill climbing to get back into the woods to mow old logging roads where I drive my RTV1140.