I was recently looking to buy a cheap Android phone with dual SIM. While looking at phones I went to checked out the DTEK 50. It ticked all the boxes apart from the lack of dual SIM and hence I didn't go for it. I believe blackberry/TCL should include this feature in it's phones as it it really convenient for professionals, businessmen and frequent travelers (the main TA for them)
BTW I went with the Moto G4 in the end. Great phone and it has Nougat