last page bottom space/margins

Q.1. I have a Big Band chart and would like to add bottom space to the last page of the piano part (4 staves on all pages but 3 on the last page). When I add space by appending a vertical frame in the piano part, this is automatically applied to all the other parts. Is there a way to indicate the vertical frame in just a single part? (I'm using v 3.6.2: my 13 year old laptop won't support v. 4.)
Q.2. I would like to have the top margin for page 1 be 10.0 and larger for all subsequent pages in the piano part, but I only see controls for even and odd pages. Is there a way to indicate top margin for all pages except page 1?

Thanks all. Musescore is delightful.