Selected flux profiles along the jet axis in the full mosaic (without deconvolution). Top panel: Hα profile (grey) without scattered emission subtraction showing the components of the fitted model. The line emission at the source peak was fitted with a Moffat function (dashed black line), and knot peaks were fitted with Gaussian profiles (dashed coloured lines). Lower panels: flux profiles in three key FELs after scattered emission subtraction (see Appendix A). The tentative and detected knot centres are marked with vertical blue lines, showing their correspondence to the features in the FEL profiles.