hi alimommy
Sound like you are doing really well already, in answer to your questions;
DS put himself on 4hr easy at little over 3months, here are some signs of needing to transition:
https://babywhispererforums.com/index.php?topic=41061.151. Not taking as much at a feed (baby not as hungry at 3 hours)
2. Erratic Night Wakings
3. They are extending their awake times
4. Starts taking 45 minute naps
I know it goes 'against' EASY, however if you feel you are in a transition stage, you really have to watch his cues and let that be your guide - it may be usefull to keep a log
https://babywhispererforums.com/index.php?topic=6208.0 so you can track when your LO eats, etc.
Do you think your LO may be going through a growth spurt?
Was your LO napping longer before EASY?
Do you want to post us your routine?
The 3 - 4hr transition can be tricky for any mum to get through, even if they have been on EASY for ages, so try and keep at it - I know its a difficult stage.