Traffic-lights for Jira Cloud already contains a tab „import“ supporting the migration of related data from Jira Server or Jira Data Center into Jira Cloud:

On-prem field types

The importer is capable to import my “Traffic-Lights for Jira” (Server/Data Center) as well as the data of “Simple Traffic Lights for Jira” by t2consult, not offering a Cloud solution currently.