Something to be aware of if purchasing or using the SG-31R.
After your recommendation I'm going to buy the SG-31R as it sounds like a simple and very useful item. However, reading reviews at B&H there is many who highly recommend it but have had problems removing it from the flash shoe. The locking detent pin often gets stuck on the flash shoe contacts and becomes very difficult to remove. The quick-fix is to remove the pin with needle-nose pliers.
It is currently " temporarily out of stock" so maybe the manufacture has taken notice and is working on a modification.