Creating Gant Chart based on Card's internal calendar timeline

[RCI 智森永續設計顧問有限公司]

I seek to make a visual, easy-to-understand progress report for my boss. Among others, my challenge is to make the charts based on calendar dates (past & future) within each Trello card rather than based off the Trello card’s deadline itself. In other words, I want to include my checklist items in my charts based on their due dates instead of deadlines.

Any suggestions of how to do this, potential companies to collaborate with, or ways to do it on my own with little software integration? Currently talking to Bridge24's team but trying to see what other options exist.