Shortend the command that updates your score from:
execute unless score @s z.leaderboard.copy.deaths = @s deaths run function highscore:refresh_score/sync_init {"score":"deaths","score1":"z.leaderboard.copy.deaths"}
to
execute unless score @s z.leaderboard.copy.deaths = @s deaths run function highscore:refresh_score/sync_init {"score":"deaths"}
made a new format key "remove_0s" that just removes 0s from the leaderboard if its equal to 1
made a new clear command
/execute at @s as @n[tag=leaderboard.marker] at @s run function highscore:clear/clear_zero
clear all 0s in the leaderboard