OK, here is my take on riding during the spring thaw period. Certain trails and trail segments are dry enough for riding before others. Any controlled area such as the Limerick requires essentially all trails to be in more or less the same state before any of them can be ridden. That call must be in the hands of individuals responsible for the particular area. Those responsible will take several factors into account: past experience, current conditions, expected opening traffic, etc. Therefore as a rider and a BMA director I would not ride any controlled area without management OK.
Calabogie crown land--to my knowledge--is not under direct and active supervision. I therefore assume riding there always falls under individual good stewardship directives. Always means during the whole year and not just spring thaw. I was riding Calabogie last Sunday, March 25th--a full month before I would typically think of riding Calabogie! Was I practicing good stewardship? I believe so and here is why. I was out with one other person (never ride alone). We rode an area of Calabogie--M&M corridor--that experience told me would have some of the driest trail in the area. If we found a soft area we rode around it or where careful to have minimal impact--no looking for mud bogs. We cleared some trail hazards we came across and we picked up some accumulated winter garbage. In other words, we where not only riding for ourselves we where practicing good stewardship for all crown land users. That is what the BMA asks of all members all the time.