By "SEL" license, I'm assuming you mean you have an ASEL certificate. If so, that's a good thing since you need a valid airman certificate.
It's not hard to submit a petition for exemption -- and the other documents that go along with it. It is very time consuming though. Make sure you read the requirements careful and include everything in your petition. If you miss anything and/or forget to submit a document, the FAA will reply and let you know. That will no doubt increase your wait time by months though.
I have had an SEL for years.You will still need a pilots license after you get the 333...you are asking for exemption to certain FAA rules (type exceptance etc), you will not get a request approved if you ask to have someone other than a licensed pilot be the PIC on the drone