That’s the main reason why Horo suggests installing to a temp folder and moving the content manually. Make yourself an empty folder on your HD and install it there, then move stuff around yourself.
Bryce is the easiest to deal with, but it does have it’s little quirks, when it comes to the installers.
Personally I deal with all my content that way, because I am fussy as to where things go, and whether I have an installer or a zip I always use a temp folder an rearrange myself.
Don’t let the installers overwrite anything. THey can be bullies. 