If you have never been to a Moot, you should come, don't over analyse While you can "come in through the back door", it doesn't gain you all that much and will involve trespass or fence climbing and bushwhacking. There aren't many places to cross the rivers, so you will be coming down the Merthyrmawr Road anyway. Ewenny isn't far away and I am sure someone could give you a lift, it would be much less to ask than for them to do a run all the way to the train station (although people do get picked up from there too, most years). Main problem is that historically there is little or no phone reception on the campsite, so you can't count on giving someone a call when you are ready for pick up. Maybe this will have improved this year, at least O2 thinks it has good cover there but who knows.
Have you looked at the Bridgend 303 bus that goes to Ogmore? This is a stop, and is as close as you can get to the camp on public transport. Google coordinates: 51.481449, -3.605373, from which you cross the Ewenny River, and walk North West to cross the River Ogmore by another foot bridge and on to the Merthyrmawr road.
https://bustimes.org.uk/services/SMAO303
New In Road from Ewenny to the turning down Merthyrmawr road isn't suitable for walking really, no footpath and the traffic can be fast.
Have you looked at the Bridgend 303 bus that goes to Ogmore? This is a stop, and is as close as you can get to the camp on public transport. Google coordinates: 51.481449, -3.605373, from which you cross the Ewenny River, and walk North West to cross the River Ogmore by another foot bridge and on to the Merthyrmawr road.
https://bustimes.org.uk/services/SMAO303
New In Road from Ewenny to the turning down Merthyrmawr road isn't suitable for walking really, no footpath and the traffic can be fast.