İs there any news on substance support? Are we waiting foundry to update substance plugin?
Yes, it's all done - and full support will be in the next release of the Substance plugin for Modo. I will put together a video demonstrating this in the next few days.
Also octane beta version of octane (3.06 Test3) has adaptive sampling option. Do we able to use it with modo plugin?
Yes, the latest 3.6.3.117 test build above includes AS. See the 3.6.3.117 video at
https://render.otoy.com/forum/viewtopic.php?f=34&t=59793 for details.
Also is there a way to globally set rounding edges value for meshes with multiple materials?
No - round edges need to be set at the material level.
Paul