The post in here explains it I believe: https://www.ff6hacking.com/forums/showth...ht=normali
Raising the CMP #$0C for Gogo to 0E or 0F (or higher) should allow for the guests characters Like Leo to equip them I'd imagine. EA EA might allow for that also. Keep in mind though that if a guest character does not take an esper off before they leave, it will result in losing the esper/magicite forever.
Also by default the guest character(s) won't be able to learn the spells from the espers, or even cast spells like normal characters - more complicated work will be needed if you were planning on that. Same with Gogo and Umaro.
Raising the CMP #$0C for Gogo to 0E or 0F (or higher) should allow for the guests characters Like Leo to equip them I'd imagine. EA EA might allow for that also. Keep in mind though that if a guest character does not take an esper off before they leave, it will result in losing the esper/magicite forever.
Also by default the guest character(s) won't be able to learn the spells from the espers, or even cast spells like normal characters - more complicated work will be needed if you were planning on that. Same with Gogo and Umaro.
We are born, live, die and then do the same thing over again.