Here some experience I have with this pseudo device adding. If you add multiple pseudo devices to assign different startup codes, you must select devices of different brands (but the same type), because if you add two pseudo devices of the same brand and type and if you change the ir-code of one of them it automatically changes the ir code of the second pseudo device (is this a bug?). The same holds for changing the delays. This doesn't happen when the two pseudo devices are of different brands.
Another note, if you make a smart choise for a pseudo device you do not end up with useless command pages in your activities. A smart choise is to add a pseudo device which is already in the activity such as a home theater center for watching TV.
A not so smart choise is adding a pseudo TV, this extends the watch activity with another screen in which you have to select the TV for the watch activity. Normally you would have: watch -> activities on the bottom but then you have watch -> select TV -> activities on the bottom. This is probably usefull when you have a projector and a TV on wich you can watch.