The client is looking for a very experienced QT developer with Graphics and Math skills, to guide their team with correct and optimal QT usage.
The team has already implementation using QGraphics which they are not entirely happy about, and their assumption is that they are just missing QT skills across their team.
They do not stick to any technology just because they already spent time on implementation. They are looking the best possible approach. Flexible. Reasonable. Working on future proof solutions.