Series 1, 2, 3 to GP

I was replacing the silent blocks on my bike when I noticed a small hair-line crack on the case where the block mounts.

At first, I thought I might have caused it during the installation, but looking through old photos on my phone it appears it was there at least a year ago when I was installing a new top end.

I tried to look further back to 2014 when I first put the bike together to see if the crack was always there but the photos are too vague

I was curious what everyone’s thoughts were, Should I take the motor to a welder and have him burrow out the crack and weld it back up or just go on my way and check and see if it gets worse?

Thanks

Tom