We have set up a "Number Field" named "turnover" which is only present for the "Requirement" issue type.

If you now start searching for e.g. "updated > '-2d'" and include the "turnover" column, you get the message "Note: Not all the fields below are shown in Issue Navigator for each issue (eg custom fields which are only per-project and/or per-issue type).".

What this actually means is, that the field "turnover" will not be included in any view (like "Excel (All fields)"), even for the issues which have this field.

Could you please provide the ability to include columns where only some of the searched issues provide values?

Also in the meantime something like "Note: If a field is not available to all queried issues, it will not be shown in Issue Navigator (eg custom fields which are only per-project and/or per-issue type)." would be a more appropriate warning in my opinion.