Solo Duties Difficulty Select
the difficulity only appear after you fail them once, so it's only there if you failed and lost time regardless (unless you fail the 1st few seconds in and go for very easy, it really makes a difference)
That is simply untrue. You are presented with a difficulty selection upon beginning any solo duty.
As shown here, from my own (failure-less) run: 
الجولات الأخيرة
المستوى: The Ghimlyt Dark
المستوى: The Drowned City of Skalla
المستوى: Ihuykatumu
المستوى: Sohr Khai
المستوى: Hullbreaker Isle (Hard)
