Yup - was able to get to the point where we got the same error as you did (including the next step with the great memory leaks).
Will see what the performance is when implementing your current hack and report back. Would be fantastic if the experts could chime in on this one…
It’s truly a shame that sparse matrix operations present such a hurdle, as I was looking forward to writing this paper with a Pytorch library. However, it seems more and more like I will have to revert to Tensorflow instead.