I'm asuming you're using (2) 100' sections of hose coupled together, all wound on the same reel? We do the same thing, as well as 200' on the water supply hose reel. However, the less hose you actually use, the better. More length of hose used makes the pump work much harder than it needs to.
When we set up, if we only need 100' of hose, we uncouple the sections and couple directly into the machines. If we have a small area that requires additional pressure hose length, we couple it to the remaining hose on the reel and finish it that way, or use a 50' we always have in our rigs. When you're done, recouple the hoses on the reels & wind up.
I've found that even when you lock in your reels, you still end up pulling some of the length of hose out to get it tight again. Also, when using hot water, your pressure hose will heat up & burn the grass. We try to leave as much as we can on pavement, and move the hoses around as often as we can. We've learned to tell the customer they may have some burn marks when we're done, but the grass root isn't affected. so it will grow back. If it's a really dry summer, it's hard to avoid. Telling them upfront will save you some headaches later. Good Luck!