About CallSafe indicates that the Ringback calling feature does work with CallSafe. When I was testing the product features it was working ok. There is a 45 minute time-out for Ringback so if the called party is on a long call then Ringback will drop out.
What's your experience?
Thanks @Gondola, that's welcome news.
Early days in my testing, but the called party in each case is renowned for often making lengthy phone calls, so that 45 minute threshold may well have been exceeded. I now suspect that may be the issue here, but will continue to monitor and report back here if I find that's not the case.