Iran is Islamic. The Chechnyans are Islamic.
Yes, Russia has been helping Iran thanks to Jimmy Carter who transitioned Iran into a Russian ally from a Western ally.
The technology that Iran develops, will be given to terrorist groups. That information will proliferate across the region.
There will be payoffs. Technology and hard objects will be transferred to terrorists.
Iran has no control over where those things will go. What’s more, it doesn’t care as long as it doesn’t blow up on it’s soil.
This will make international arms control almost impossible to effect.
Chechnya is also under control through Putin's puppet dictator Kadyrov. Russia has a long history of using Islamic terrorism for its ends.