I don´t think you should overdo it either. Not that experience as a DM is counterproductive. But it is not necessary to be an assistant for years. You can just become an instructor, and continue to DM, or be an Assistant Instructor, or team teach, an OWSI rating will allow you to do all that. Don´t feel you have to wait. Once you realize what an IDC and IE are all about, you realize that if you waited 2 years to do your IDC, to be more prepared for the IE, you wasted your time. I just want to make the point straight and honest. Being a DM for a long time, assisting different instructors WILL help you with teaching. But it WONT help you much for the IDC or the IE. My point is, if you are interested and capable of doing the IDC and the IE, being an instructor and offering your services as a DM/AI will allow you to continue to learn, to team teach, to assist someone, and also will give that "main" instructor much more flexibility in how you can help him. Most IDCs/IEs are of much lower standard than what many people on this board believe an instructor should be (including me). If you have the means, and you want to do the IDC, and IE, go ahead.