Long notes should be held for at least one beat. Faster release timing is too difficult for players of this level.
suggest you change the 1/2 LN into single notes
https://osu.ppy.sh/help/wiki/Ranking_Criteria/osu!mania#-easy
after considering, it might be difficult in a general map which is not layered with LN mainly.
I personally think this kind of usage may be fine when it comes to like full LN patterns since players can easily save trouble to distinguish which should be held and which not, just held all
but it is just a really really personal opinion so i guess i would look for someone else to confirm if it is acceptable!