40 Paragon (Hbeta only)
30mm UFF
17.3 Delos
13 T6
10 Ethos
8 Ethos
6 Ethos
5 T6
3.5 T6
First:
Congratulations on your new scope.
Second: My 16 inch has a focal length with a Paracorr 2 of 2070 mm, just about 5% longer than yours.
Dick's comment that you have two sets makes a certain sense to me. What I see is parts of two sets. The focal lengths all work together as one set but the eyepieces are quite different physically. The 13mm-10mm-8mm-6mm set is a nice progression but the 13mm T-6 is tiny little eyepiece that has a very different presentation than the 10mm Ethos.
I have both the 13mm Type 6 and the 13 mm Ethos as well as the 13mm XWA.. Crazy but.. You might consider replacing the 13mm Type 6 with the 13mm XWA.
I have the 20mm XWA, you like the 17mm Delos with a filter, so it may make more sense. For me, the 20mm - 13mm is very workable and for filters, I sometimes remove the Paracorr to get a brighter image. I believe the 13 mm XWA is actually 13.5mm so without the Paracorr it would be equivalent to a 15.5mm eyepiece. That might be enough.
I also have the 5mm and 3.5mm T-6s. Again these are fine eyepieces but they do not "flow" well with the Ethos. The step down in AFoV, the much smaller physical size, the shorter eye relief, they just don't work together well for me.
The 4.8mm XWA and possibly the 3.5 mm XWA fit better for me.
I actually have two sets..
30mm UFF or 28mm UWA, 22 mm Panoptics, 16mm Type 5, 13mm, 11mm, 9mm, 7mm, 5mm, 3.5 mm Type 6..
28mm UWA, 20 mm XWA, 13mm, 10mm, 8 mm Ethos, 7mm, 4.8mm, 3.5mm XWA.
I find mixing the two sets does not work so well, bumping the AFoV and eyepiece size up and down.
I prefer the 28mm UWA to the 30mm UFF. It has a 12% wider TFoV along with what I perceive as better transmission.
You have a nice collection of quality eyepieces. Don't rush out and make changes..
Regarding the 20mm LHD, I have one, I am still feeling it out. I believe I am seeing some off-axis astigmatism and maybe some EoFB. It's nice because it's lighter than the 20mm XWA but I prefer the view the 20mm XWA provides.
Jon