We seem to be way off-topic but the issue of "legal GEDCOM" is moot. From the draft 5.5.1 spec:
The field sizes show the minimum recommended field length within a database that is constrained to fixed
length fields. The field sizes are in addition to the GEDCOM level and tag overhead. GEDCOM lines are
limited to 255 characters.
For the EVEN tag, the minimum recommended size for Description is:
EVENT_DESCRIPTOR:= {Size=1:90}
, i.e., 90 characters. RootsMagic exceeds that as it truncates at 100. If the GEDCOM line is limited to 255, then the Description can be 255-7=248 characters.
But that's not all. Note that this is for a "database that is constrained to fixed length fields"; RootsMagic is not constrained that way so it can support a longer one line descriptor if the GEDCOM line is allowed to be greater than 255 characters.
Moreover, the draft spec says:
However, the CONCatenation or CONTinuation tags can be used to expand a
field beyond this limit. CONT line implies that a new line should appear to preserve formatting. CONC
implies concatenation to the previous line without a new line. This is used so that a text note or
description can be processed (word wrapped) in a text window without fixed carriage returns.
FTM exports long Event descriptions using CONC (and CONT, I think) and now RM7090 recognises them on import albeit shoving the assembled value into the Note field when, arguably, it should leave it in the Description field.
I don't see any illegal GEDCOM in supporting drag'n'drop of long Event descriptions and preserving them in the Event descriptor field. What seems illogical or short-sighted is to change their location to Note. The motivation for doing so is the little one line field display for Event Description in the Edit Person screen. The solution is to enable a Note Editor style editor for Event Descriptions that are long, not changing where they are stored and outputted.