Venno made a hack to increase the maximum value for movement some time ago, so I bumped it up to 30. I use this to make penalties for weather less harsh (e.g. ×0.75 mov in rain instead of ×0.5; ×0.5 for fliers) as well as the armor/mounted bonus/penalty indoors. I also re-named mountains “hills” and made them give an odd-numbered movement penalty, so moving through a large swath of hills is a bit faster than going into the hills from plains.