Blink and Dodge?

Is there a way to allocate Blink onto a build but when you are within the time-limit, you can still roll away? I don't understand why it doesn't just roll when a "blink" is on cooldown. The only way I can find to use roll is to switch weapon sets and have Blink off, but when I really want to blink + roll away, it takes too long to "switch" weapons as the enemies are already on you.

Am I missing something to how this mechanic should work? I feel like I either have to pick dodge rolls only, or fly with 1 blink then wait 4 seconds hoping that one blink was enough buffer I needed.

Thanks

(Also, really hate 1 death on maps when there are 6 portals)