300 repetitions/piece

I would say the practice is not boring not painful but enjoyment in itself.

— for a song with full score for both hands, I usually target 1000 repetitions/piece

— for a simple melody-n-sing piece as described in https://1330152open.wordpress.com/wp-admin/post.php?post=23731&action=edit&classic-editor

aim at 300 repetitions/piece. Don’t need to be really flawless.