I had my first visit a couple of weeks ago - well, second really, but the first was when I initially set up these tyres as tubeless: one tyre had a known hole from being used with tubes.
Like you, I found it took longer to seal than I’d expected. Next time, if I saw a similar volume of sealant being expelled I would get in early with a rasher. As it was, in the dark and pissing rain, minus my glasses
I wasn’t confident and as time passed I could see that the sealant was going to win. It would have been rideable, just, but I had a way to go so added some CO2.
Despite my mudguards preventing most of the sealant getting everywhere, there was still a significant amount of cleaning to do, largely because in the rain etc it took me a while to recognise what was happening. Easily cleaned off though.
Like you I have not been able to find the puncture, even when I looked for it with the tyre deflated when I replaced the CO2 with air when I got home.
Back to usual performance - I add literally 2 or 3 PSI a week.
The rear is getting quite worn so I think I will soon do a proactive replacement. It will be interesting to see how it looks in there. I am confident that the Silca sealant does not 1) completely evaporate and 2) eat rim tape, as has been reported.