There's no increment. Nodeflair even states that they cannot confirm the pay. Like many have said in the past, it's hardstuck 5k for the first year, you might get $150 after a year but that depends on team.

Also shortlisted means "back-up / waiting list". Background checks do not take 3 weeks, they just want you to "wait" so that they can release offers in batches and give them 1 week to accept. The ones who reject the offer, they will give their placing to those in "shortlisted" waiting list.