All of the 270 AMs I have built use a 1-8 twist. This is slightly more then needed. I believe a 1-9 would also work just fine but Lilja did not offer a 1-9. I have used some Rock barrels in 1-8.7 twist that worked very well.
For the 270 WSM, I would likely stick with a 1-8 twist. Again, probably a bit more then needed but fully adiquate is much better then marginal.
I designed a round based on the 270 WSM simply for a 1000 yard BR class chambering using this exact bullet. With a 2900-3000 fps velocity in a 26-27" length barrel, it would be extremely impressive and would have outperformed the 7mm WSM loaded with the 180 gr Berger even if that round got 3000 fps.
In the end, I figured a properly built 270 WSM was so close that it was not worth the investment to move the project past that point.
Simply put, I think it would perform great.