`/wot/requirements-of-pending` is too long to respond on Ğ1
With only 63 identities in the sandbox, this URL is still a very costly call. For the node, it requires a lot of disk access + CPU (distance test), and for the caller it might end in an HTTP timeout, which during a sync leads to have an empty sandbox for the caller.
Maybe the distance computation is not required in this URL, but should be let to the /wot/requirements
URL. Maybe other points of improvement (DB access) could be investigated as well.