Depending on how many overlaps you have, Advanced Actions might be a possibility. You can make one decision "If the EE ID entered is 1 OR 3, go to slide 4" instead of two ("If the EE ID entered is 1, go to slide 4" and "If the EE ID entered is 3, go to slide 4"). That might bring down the number of decisions... although if you still have 30 slides as possible destinations, I guess you will still need at least 30 decisions.
If you have the time/inclination to look into JavaScript, that's personally where I would go. But perhaps others on these forums will have another possibility. 