Recall and Trust

Hi I'm looking for some general advice, I've been working with a trainer to help my 15mnth old husky learn recall, it's going relatively okay but I've hit a bit of a wall, apologies in advance if this is a silly question, Athena is a "family member didn't research the breed and now she's my responsibility" case which I have fully taken on and am happy to learn and grow as she does.

Anywho, shes got short distance recall on and off line almost totally figured out, bit more work and she'll be great, we have a basketball court in the middle of a big park/field that I allow her off lead time in as it's secure and big enough to throw balls and toys and do basic recall and other such training in so she can't decide to just bolt off access the field, shes great! But here's where I'm seeing the oncoming brick wall:

Where do I go once I'm comfortable with her recall in the secure court area? It's a high distraction area and I fully realise that inside the courts and outside are two different worlds to her despite it only being separated by a see through fence, she's doing great and while I have a 20m long line Ive been told to try using im a little scared a I guess? I believe she'd do really well but in the past if she gets a good enough run up she can and has completely broken her last owners fingers with the running speeds she gains, I fear I may be put in that situation should we move onto open field work. Again sorry if this sounds silly. Maybe I'm moving too quick, We've been in the enclosed courts for a good half a year now and Im not sure how to take the next step when i feel she's ready.

She's got an amazing temperment but a tendancy to approach other dogs without thinking, hence her previous owners accident and I really don't want to be "that owner" in the park, you know? She's not aggressive, just- "I must approach" which is where i fear that dreaded running speed of hers on a long line. I'm committed to learn and fully want to grow with her I think I just need a bit of guidance here.

Thanks