If you have a partition that cross multiple swimlane, the partition is separated in multiple occurence. Each partition have the same width which is not correct as it should be "compacted" inside each swimlane.
@startuml
title partition over swimline
|#dee4e8|p1|
|#c4c9cd|p2|
|p|
|#daf0fe|p3|
|p1|
start
:something;
partition testP {
:on p1;
|p2|
:on p2;
|p3|
:on p3;
note
this is a long text note to have much bigger size on p3
end note
}
|p1|
stop
@enduml