Right now, there isn't a way. That's because the brokers in the US aren't set up to receive such payments, and the brokers in the UK aren't set up to make such payments. But as the treaty recognizes US/UK pensions as interchangeable, it may be that one day in the future they will be. I doubt that future day is too far away. There's possibly even a way around it today, but I'd have to do a lot of research on it. I charge for research time, so it' s not a topic for the forum.
There's a lot of tax benefits for paying into a plan; these benefits may far outweigh any fees associated with keeping your account active. Another major benefit is any matching your employer may provide to the plan.
Further, if you are doing this yourself rather than using your employer's plan, you can shop around for lower and/or fairer fees. Don't buy from ANY so-called IFA who charges commission. Only buy from people who charge a % of assets under management. These are the only fee structure that align your interests (growing your money) with theirs (making a lot of money off of you). Commissions incentives them to invest you in something that pays a high upfront commission rather than the product with the best long-term growth record. Further, the I of IFA may stand for "Independent", but in fact many brokers are tied to providing a single company's product, or a small range. Only buy from a real broker who can any company's product. Even better, opt for one who can also sell stocks, shares, and bonds as well as Unit Trusts and Investment Trusts.