Yeah I saw Vaishali & Javier's presentation [1] at LPC last year! Great stuff, & certainly available to use now rather than when SFrame becomes available and supported.
In the same spirit, it seems that the .eh_frame -> BPF unwind table process could be (relatively) easily modified to produce SFrame, which you could attach to the binaries if you have a trustworthy way of doing that (which is... a big if). So that once SFrame support becomes available in the kernel, you could apply it to applications without rebuilding them.
[1]: https://lpc.events/event/16/contributions/1361/