Polytonality in Musescore

So recently, I heard about this concept called polytonality, where different parts in a piece of music would play in different keys. For example, in a string quartet the first violin will play in Ab major, the second violin will play in C major, the viola will play in Eb major, and the cello would play in F major. I thought this was pretty cool, so I decided to try this in Musescore. However, I ran into a problem when I found out that inserting one key signature would revert all of the key signatures in all of the parts into the same one. I don't want to use accidentals, since that would take a long time and be very hard to read, so does anyone have a suggestion on what I can do to get around this problem?