how does one sync audio data without ADAT sync

[glittle]

I've been using an RME Multiface for years. Possibly the best audio gear purchase I've ever made. Love that (and their drivers).

One of the ways I use it is to copy audio data from my projects to projects on other people's computers/software, *in near sample-accurate sync*. I've always used the ADAT sync for this. Hook up the two pieces of equipment, locate to near the area of audio I want to transfer, and go.

Now however it seems adat sync is getting hard to find on gear, at least RME gear. I wanted to get a new interface, as well as recommend them to recording partners.

So how does one do this these days without using adat sync? Neither midi time code nor smpte are sample-accurate, are they?

One could of course render the tracks one wanted to transfer into individual files and copy those over, but that only works when the start points of the files is zero-based so they can be locked to the correct location. This method is a fair bit more fiddly and a hassle compared to just syncing up and play/record.

Maybe I'm missing some other technique?

Thanks...