You are not experiencing scaling interpolation directly but rather indirectly through sub-sampled chroma. Nearly all video uses sub-sampled chroma.
If you use File > Export Frame… the image is coming from the player, and the player always uses sub-sampled chroma to reduce the data transfer over the PCI bus to a GPU or video card. Then, the sub-sampled chroma is up-sampled to make a RGB image. One way to remedy this is to use the Export panel with a preset from the alpha or stills category. These ask the engine to use RGB(A) for processing. Of course, this will only work if your video is RGB(A) or YUV 4:4:4, but I do not know what you are using.
Also, please be aware there are some filters that only process in Y’CbCr (aka YUV) sub-sampled chroma, but that is rare. There is a list in this reply.