I would say yes. If you are staying for a number of days, the cost of an added day of tickets should not be too high. When we stayed on site we would usually visit a park in the afternoon/evening. We would get park hoppers that included the day of our arrival and departure. With your 11:30am arrival you will probably be at the resort by 1pm. I recall we had about a 50/50 chance of a room being available with a midday arrival.
If the room was ready we would head there and unpack. We would then pause for a leisurely lunch to decompress after the travel. After lunch we would head off site for some food shopping. After that we would wander over to Epcot. An easy walk as we stayed at the Boardwalk.
If the room still wasn't ready we would have our leisurely lunch hoping that the room would become available. If the room still wasn't ready we would wander over to Epcot until we got the room ready message. Then we would go back to the resort, unpack, and then head off shopping. If we weren't feeling too tired we might head back to Epcot for an evening snack.
Wishing you a magical trip!