I'm working on jira-cloud add-on. Since using custom fields is limited I've decided to use JIRA entity properties instead. I don't want to show my custom data on standard JIRA views, so it seems to be a good choice.
But I can't find a way to retrieve JIRA entity properties for scope of issues by one request. I have to use REST /api/2/issue/{issueIdOrKey}/properties/{propKey} instead. It is a very inconvenient because number of issues may be huge.