I would love to have it here for wolf trapping. When you are trapping an animal that is only coming through every two to three weeks, it would be great to have the flexibility to not have to check as often when you know nothing has been by your sets, and it would allow you to lower the traffic and scent to avoid spooking wary animals. Also with a longer check time you could run one drainage (with tracking snow) and know if they haven't crossed it, there is no need to check the next two drainages you have traps in, because they haven't been there. Our 72 hour check provides some advantages for keeping scent and disturbance down, but the option of a 96 hour check would be nice.
I believe a lot of the thought behind a 96 hour check is that it allows working people to check on the weekend and Wednesday, while a 72 requires either both a Saturday and Sunday check on everything, or a rotating schedule with different days of each week, and multiple days during the work week, most weeks. The real advantages would be on a longer line, where you could spend the weekend doing maintenance on sets and stuff, without having to rush to get them all checked in one day. While your midweek check could be a faster run to cover everything while leaving maintenance until the weekend. This is a common practice even on shorter lines and shorter check times for guys checking before or after work, but the longer check time opens it up for a longlining working man.
Obviously some thought needs to be given to equipment choices on longer checks. Lethal sets are not always the answer either, if you don't have low enough temperatures, spoilage will be a major issue on longer checks of lethal sets. As will predation and scavenging on catches. I don't have experience with fox trapping, but have always heard they have fragile feet, so foothold choice for minimal foot damage would be important. Some thought also needs to be given to possible secondary or bycatch animals and how they will fare in the equipment chosen.
