I wouldn't understand why not to license it, but that is of course a personal decision.
The only thought I would have, is that expectations will be higher if a commercial product. There are few behavior things with the express that might want to be addressed (or perhaps the literature be more specific). For instance, the express currently does not let the top few channels be programmed for the light curve values. The dongle is seems to require a full universe written to it every time (which is not exactly entec pro consistent). The start code value field is not used. None of these are issues for a DIY, but if commercial, I would expect those items to be addressed, or documented clearly.
But clearly, the LE is a nice product, no reason not to make it available.