Replace gantt bar functionality lost with Project Online's retirement

Project Online is being retired in September 2026.  The alternative Project Portfolio Management solution is a model driven app.  However, there is no viable alternative with a model driven app to replace the functionality we are losing when it comes to the Gantt bar customization options. In Project Online's Project Center, we are able to view all projects in a customizable table to show any project level fields we choose on the left and customizable Gantt bars on the right. The Gantt bars for each project can represent any custom start/finish fields we choose, can be represented as a top bar, middle bar, bottom bar, top line, middle line, bottom line, etc. and multiple custom start/finish fields for a given project can be combined into one Gantt bar.  For example, the start/finish can be a bottom bar while the baseline start/finish can a top bar.