If I got a higher rank in ranked flex than rank solo do i get the ranked flex border next season?

The queue borders will probably be separate, but overall they haven't told us what they've decided for what will show in normals SR.

You'd have the border for Flex loading screens but definitely not solo/duo ranked and probably not in norms.

Back in prior seasons when there were multiple ranked queues, the border you load with is the border you got last season in the queue that you're playing in. And I think normal games used either the highest or solo.