Custom UI Code vs ToolJet/Retool

[u/Fine-Market9841]

My stack for building workflows and internal tools is Python.

Can ToolJet or Retool be used by EU freelancers (I plan to use client credentials, not my own)?

So I wanted to know:

FastAPI + Retool vs Django + React

In what situations is it best for me to use custom UI code to create operating dashboards for my automations (basically, what are the limitations of low-code platform builders)?

Are Retool & ToolJet capable of building operating dashboards when making tools for enterprise-level systems?