No it would be pointless for me to take micrograms of Iodine for a deficiency that requires milligrams to replete.
This is not at all unusual from kelp unless you believe those that profit from Iodine in the form of Lugol's or iodoral.
in a mere 1 teaspoon of powdered high potency kombu/kelp I receive the amount in a tab of Lugols at the cost of 1/4 of a cent. probably 100 times cheaper than an iodoral tab
Seaweed is the best source of natural Iodine as it is a complete food with all the cofactors already included. One needs alkaline minerals and sugars and other co-factors unamed to be considered the best source.
The form you mention might be preferred only for serious diseases that are iodine defiency derived.