Right now osu decides on its own what to display in your best performance.
What I'm asking is not to change this behavior, but rather, when a certain play is already in your best performance, give the player an option to "lock" that play which means that this play won't move away from best performance even if you get enough plays on other maps that will normally push it out from that list.
Obviously you'd also be able to unlock plays, and in the case that you do that, they would either stay or get pushed out by other plays that give higher PP on your account.
Example:
Also, when people view other people's listing, they should be able to see which plays are locked and which ones are not, to know which plays a player personally values and wants to be in their list.
What I'm asking is not to change this behavior, but rather, when a certain play is already in your best performance, give the player an option to "lock" that play which means that this play won't move away from best performance even if you get enough plays on other maps that will normally push it out from that list.
Obviously you'd also be able to unlock plays, and in the case that you do that, they would either stay or get pushed out by other plays that give higher PP on your account.
Example:
Also, when people view other people's listing, they should be able to see which plays are locked and which ones are not, to know which plays a player personally values and wants to be in their list.