With the recent emergence of numerous accelerators promising large-scale computational speed-ups over traditional CPU-based applications, heterogeneous computing has become of increasing interest to the scientific computing community. However, producing portable code without sacrificing the performance available from vendor-specific libraries remains a challenge, for example, when using discrete Fourier transforms (DFTs). An example of this is GROMACS, which must consequentially maintain multiple GPU programming APIs and backend DFTs libraries. In this talk, we show how the oneMKL interface library can be used to allow GROMACS to use just the SYCL implementation while retaining the performance of vendor-optimized libraries for DFTs. The oneMKL interface library makes this possible with minimal overhead using SYCL backend interoperability.