PI check my AS monthly... Especially after a rough tow. The AS flexes a bit and can create some issues. If you do it regularly you may find NO BIG PROBLEMS! And if you fix the little things, they rarely become "huge".
Our AS like so leak around the front cap joint and window on front center curb side. So I have learned to check it more often, closely... And I rarely get dampness in the area now.
Once a year visit for a "full reseal" at the AS dealer may be good for "overall" security of leaks...then if you can indicate "problem areas"( because you have done regular checks), that will assist the technician on where to spend more time.
Pressurized "leak test" may be a good place to start then judge frequency based upon your AS and use.
Peace and Blessings..