Hi John, yeah it's probably easiest to run Inset before you do the flow rather than afterwards - that will give Inst a more simple object to work with.

I can't really tell just by looking at your screenshot, but is the O character possibly made up of a bunch of segments instead of only one single long segment? If it had multiple segments that would mean that the "side walls" of it would also be broken up into multiple faces instead of just one side wall face, and having multiple broken up faces like that instead of one big single face there is probably going to make things more difficult for Inset/offset type operations as well. Especially if the different pieces are nearly smooth to one another but just barely not - that will make surface offsets try to do an extension like it would need on sharp corners but things that intersect at a very shallow angle are more difficult for the surface intersector to handle.

Could you possibly post the 3DM model file? That would then help to take a look at the actual geometry.

For something like this where you're going to be doing a bunch of stuff to the text, it can help to simplify the initial text curves as much as possible, and the Rebuild command is the easiest way to do that:
http://moi3d.com/2.0/docs/moi_command_reference10.htm#rebuild

At some point I'll be making the Text command automatically simplify what it makes by running Rebuild on it automatically, but at the moment it does not do that.

Rebuild can help do things like take a curve that is broken up into a whole bunch of separate segments nearly smooth to one another into one longer smooth segment, then when that is extruded it will be one single face instead of a lot of different faces and that can help simplify the job of other things like offset/inset after that.

- Michael