It sounds similar to the situation we faced with my wife, who also wanted to retire early with a health condition being part of the rationale. It took a lot of work, but we got her work DC pension transferred to a SIPP where she could take 25% tax free immediately and draw down the rest to cover the gap before getting her state pension plus another work pension.
Her work pension provider wanted evidence we had had independent advice, as yours has. Happily a couple of years before, after I had had my PC treatment, we had had a one-off consultation with an IFA about planning for the future, and he was happy for us to include his details on the form without any extra charge involved.
I do see the logic, while you know what you want there is a risk you might throw away a benefit of the DC scheme like the one Francij has. The DC scheme wants someone else to accept responsibility for doing the checks.
It now seems we were lucky to have gone to an IFA (someone my late mother had used) who was happy to do a one-off consultation, most want to have an ongoing contract involving annual fees. You will have to ask around and look carefully at IFA websites to find someone suitable in your case.