I could add on Bagan and Ngapali Beach, with an intinery of:

Yangon to Mandalay on Air Mandalay
Mandalay to Bagan on a Irrewaddy River cruise
Bagan to Thandwe on Air Mandalay (does this route still exist?)
Thandwe to Yangon on Air Mandalay (ditto, does it still exist?)

I don't fancy flying on any other local airline, other than Air Mandalay, and even that doesn't exactly make me feel at ease.