Hello,
Is Load balancing possible between 2 links connecting 2 different MST regions ?
No, it is not. Two MST regions see each other as a single switch. Hence, two MST regions are like two switches to each other. There is only a single STP instance run between MST regions, and this instance determines the state of the inter-region links for all VLANs at once. In your case, the two MST regions act like two switches interconnected with two links. Just like between two physical switches, only one of the parallel links between the region will be forwarding, all other links will be blocked.
Best regards,
Peter
