You may be forgetting that with Loft objects the resolution is not derived from source splines but from the object itself.
Massively increase U segments in Loft Object...
I don't like this method for doing this sort of thing because it is quite difficult to get (and verify) identical segmentation on each side unless you symmetrize later. Also note distribution of edges, which is kinda arbitrary and not that great if we're honest.
By the time you have sorted that out for regular spacing and whatnot, you may as well have modelled it from polygons with symmetry and got a more usable base going forward ! If we definitely want to use splines, then Extrude is the better generator because that does take its interpolation and point counts from the spline, and it is trivially easy to add the little ridge bit on one end later...
Of course if you need splines for further modelling tasks you can still use the ones you have, or generate them anew from your evenly divided model using Edge to Spline...
CBR