I recommend using shorter 1/2 chains for this difficulty, as the song is really tame and calm. try to only map sounds where there are strong piano notes.
00:04:686 (20) - 00:07:803 (35) - 00:10:920 (50) - 00:17:154 (17) - 00:20:270 (32) - 00:23:387 (47) -
by deleting these notes you'll also give more emphasis to the main melody, which works really well, and you can work around it more to make engaging 1/2 chains of your liking, since this is just an example.
For the triplets usage, it's a more complex topic. Due to how simple the song is, it's hard to find a place where to put triplets. I recommend using the bass/trumpet sounds as a way to decide where to put your triplets, such as 00:13:842 - or 00:10:335 - .
I hope this helps, not much else to say as the structure is cleaner on this one!
00:04:296 - consider matching the coloring to something like kddkd or dkkdk ; to provide the typing bossa nova rhythmic support that the song offers. similarly, at 00:02:348 - a structure like either dkdd / kdkk / ddkd / kkdk ; would match better for similar reasons. (applies to the other instances which i wont list since the song is quite repetitive)