I thought that I had thought everything out, setting up my camera hours ahead of time, getting the triple-exposure working, getting every setting on the camera “correct”. Camera was level, framed correctly. I left it, and went back to other things until a few minutes before midnight.
I loosened the knobs to re-aim my camera once I knew where to center it. In the future I will snug down all the knobs even tighter, so the camera won’t move unexpectedly. I’m disappointed now that I never realized the camera lost its “level”, and yes, since I could barely see, the D750’s built in level would have been appropriate, far better than my “guesstimating”.
I will make up a “check list” for next time. I just never even thought about the remote. My brain gets filled up with “what is happening”, and I don’t get to slow down, stand back, and think what I might be doing wrong, and how to correct things. I suspect my brain was too filled up with triple-exposing, and trying to know which shot in a series I was capturing (a lost cause, I lost track, and the camera didn’t seem to tell me during image review - if the camera were smarter, it would only show me “image review” after the final shot in the sequence. Better put, I got lost in what I thought I was doing, and didn’t “step back” to analyze things and correct mistakes. After this, I will never forget the remote again for fireworks photos, and the camera will be locked down solid.
I did try varying the aperture, and the choices were way too dark, good color in “trails”, and “burnt-out with less or no color in trails”. Before I do this again, the camera will be set to 4 seconds. As I started to shoot, I did try different shutter speeds - in retrospect, I should have set the camera to 4 seconds before the fireworks even started, and left it at your settings unless something was obviously wrong.
PL5 should have shown two images, my original image when I first thought it was done, and a VC when I decided I should bring out the buildings. You’ve brought out the buildings even more, which is important, and a very nice improvement, to show the city so much better. I’m shocked and disappointed that I never even realized I had captured reflections in the water - I like what you did, but I’m wondering now if I can bring them out even more?
Looking at your finished image, and then going back to mine, the addition of reflections in the water is a HUGE improvement. I look at what I did, and it’s like I cropped out a very important part of the photo. No excuse. I had all the time in the world, but I guess I had a one track mind of “bringing out the buildings” even more. I’m disappointed in myself that I never even notice the reflections - but they might not have been there to even notice in my original image before I tried to bring out the city buildings.
To put everything in perspective, using your suggestions, I got the best fireworks photo that I have ever taken. Nobody I have showed it to would give a second thought to the mistakes that I now know I made. On the other hand, I learn very well from mistakes, and especially you, @Wolfgang and @platypus, and often @OXiDant make certain that I understand I did make mistakes, and suggestions on how to correct them - in this time, for the future. I can’t repair a wobbly image.
Making a check-list for next time is a good first step.
Finding a way to attach my ML-L3 remote to my tripod is another.
If I am using the tripod, there is a good chance I should be using the remote.
My memory was never all that good, and now it’s even less so. Thanks - I added your iCal notice (thank you!!!) with notes:

Right now, I’m very pleased. After so many years, the advice here has once again resulted in a huge increase in performance. Thank you all!!!
Added later, using your suggestion on reflections on water - using an inverted graduated filter…
MM2_0057 | 2022-01-01.nef.dop (38.4 KB)