We have the same type safe at the Towers and we've never had a problem but we did have to call for assistance once since 'someone' changed the combination without telling 'someone' else. It's amazing how many people 'might' have access to those safes but as long as you trust your staff in general..........
As far as the Kyss bag for the beach, I couldn't be bothered. Over many years and many trips we have never had a problem at the beach. We decided a long time ago we really don't need all that extraneous 'stuff' at the beach so we just don't bring it ergo we don't have to worry about it.
Bottom line on the OPs original question, what other options do you have? We never put anything in our safe beyond passports and cash. We leave our e-readers, laptops, cameras, etc., in our room and it's never been a problem. Of course, we've owned and stayed at the same timeshare for years and we know all the staff well and trust them explicitly.