Some thoughts to the improvement of the Gantt functionality:
Support different colours within the Bars. For example. If the assigned people belong to different companies. That would be an easy way to share a project Gantt with customers as they would notice their tasks quickly due to the other colour.
"Show task name in bar" checkbox
"Show milestones + milestone title"
"Show vertical line for TODAY" (additionally to the green marks that are already in the cart)
Adjustment of the columns according to the content.
If the project duration is very long, don't break the line. Please support a vertical scroll able PDF that shows the lines in one.