I was lucky to check the affinity designer forum before making a purchase for it..
The need for inbuilt auto image vectorize is really important and I guess it must be obvious for a designer tool to have support for this..
Anyone can use inkscape for tracing but it is a overhead to use other tool, then export and import of vectorized form. It's a huge drawback for affinity designer to appeal in graphic designing industry.
The graphic designer industry uses two major tools in India - ADOBE ILLUSTRATOR and COREL DRAW, and both of them supports quite extensive tracing features. Even Corel draw makes it product highlights as introducing power trace, upon improving the tracing ability. And illustrator has inbuilt support of different presets of strong tracing options.