View Timeline in Gantt per projects per weeks

I’m trying to make a Roadmap with a Gantt view.
I want to specify how much % I’ll work on each projects per weeks.
But I feel that there could be an improvement on grouping and displaying on the Gantt View.

You can see on this picture that I want to group per projects and have a quick view on percentage. To have the percentage displayed on the chart, I had to set my percentage as a display column.

But what I want is simply having one line per projects with the different % on the same line.