Summary
When migrating from Jira Server/Data Center to Jira Cloud, internal numeric entity IDs (such as jiraissue.id) change and are re-sequenced in Cloud. External reporting systems, data warehouses, and custom integrations that rely on numerical issue IDs risk overlapping or misattributing historical DC data with new Cloud issues.

Suggetsion
Provide a mechanism (or administrative capability) to define the starting value/seed in the Cloud sequence generator (e.g., set the jiraissue seed to 5,000,000), ensuring new Cloud issue IDs do not collide or overlap with existing Server/DC numeric ranges.