Okay, no worries. Apologies but I only flicked through the previous four pages and missed that detail.
Assuming that (1) water was previously able to leak in to the pods and (2) soaked into the plywood, then aside from any possible rot issues, it would take time for that moisture to bleed back out of the ply. That would cause ongoing condensation issues.
Condensation itself occurs when moisture-laden air cools below its dew point. Imagine you have a container of air that contains 10g of water vapour per cubic metre. That's what's called the absolute humidity (10g/m3).
The capacity of air to hold water changes with temperature and barometric pressure though. Ignoring barometric pressure because it's not relevant to your issues, the relative humidity (% RH) of the 10g/m3 air in that container would be as follows for various air temperatures:
11°C - 100% RH (the dew point for 10g/m3 absolute humidity)
20°C - 60% RH
30°C - 34% RH
40°C - 20% RH
As you can see, despite the actual physical quantity of moisture in the air remaining constant (10g/m3), the relative humidity varies with air temperature because warm air can hold a whole lot more moisture. 11°C air is saturated at 10g/m3 whereas 40°C air can hold up to 51g/m3.
What this means is that during the day as your pod heats up in the sun, the capacity of the air inside to hold moisture increases and will wick moisture out of any damp materials (like the plywood). For convenience let's assume that absolute humidity ends up at 10g/m3 per the above figures. As the pod cools down at night, once air temperature drops to 11°C, then the air inside will be at saturation - it literally won't be able to hold any more water. As air temperature drops further, the moisture then starts to condense out of the air.
That condensation typically occurs on surfaces because heat loss from the pod is occurring through the pod surfaces to the outside environment - ie the pod walls are the coldest place in the pod as the surrounding air chills down. Hence condensation occurs on the walls.
So ... if you've dealt with the source of the moisture (leaking seals), dried out the pods (forced ventilation) and are confident that there's no rot, then you should pretty much be done. I'd probably just put DampRid containers in there for a while between uses to keep sucking out any remaining moisture, then see how it goes without.
I wouldn't be keen on whacking permanent vent holes in them. Keep to the design intent.