Copied from JSWSERVER-25122, almost verbatim, as there was no cloud counterpart:

Summary

Currently, Advanced Roadmaps plans only support a limited number of field types. As explained in Configure custom fields in Advanced Roadmaps, the following field types are supported:

• checkbox
• date picker
• user picker (single user)
• number
• radio button
• label
• single-choice select
• multiple-choice select
• single-line text
• URL (read-only)

When trying to add more Custom Fields to a plan via the menu ⚙ > Configure > Configure fields, the fields that are not supported will be greyed out with the label "UNSUPPORTED"

Suggestion

Add support for:

• Other Jira Native field types such as:
  • Date Time Picker
  • Select List (Cascading)
  • Text (Multi line)
  • Comments
  • Version field
  • Organizations (from JSM)