When we still mowed hay with sickle bar mowers you could take the sickle out in less than a minute. It really is not a big deal. We ran under serrated sections. So you could sharpen the to of the section and it would still cut well.
Plus you would only sharpen the sickle maybe once or twice each year. That was while mowing 40-50 acres of hay. IF just on section was broken then we just use a sickle tool and replaced just the one that was bad.
You sound kind of like my Dad he would figure ways to try to save "time" doing some thing. Most times by the time his time saving device or idea was used, the guy that just jumped to it was already done. LOL HE is a college educated mechanical engineer.
An example of this was cleaning out the small hog house we had. He had it where you could take out one post and the door then you could get the skid steer into the shed to clean it out. You had to be real careful and not turn much while in the building while you where doing it. This would take him most of the morning to do start finish. I would just take the scoop shovel and could have it done in less than an hour. It took too much time removing the post and door verses the time saved using the skid steer.