I am using several gruop fields inline in one content type and it works fine if i have all or some fields with data in them.
Problem is if some fields are empty, the separator is there and it looks confusing.

In a content type i have 10 group fields inline, each having 5 fields in the group. Separator is "|".

Group Fields 1,2,5,9,10 have values in them. Only group field 10 has values in all fields.
Group Fields 3,4,6,7,8 have no values in the fields at all, but separators are visible and new line for each group field is displayed too.

In the end it looks like this:

Field 1: value | value | | value | value
Field 2: value | value |
| |
| |
Field 5: value | | | valeu
| |
| |
| |
Field 9: value | | |
Field 10: value | value | value | value | value