Another example
The curve is a bit off after merge.

I can’t select the points and slide them up cos 2 of the 4 points (to the right of the red line) don’t exist at this spot

Slide gives this.

So I either
1. Need to plan ahead better so this doesn’t happen
2. Spend ages moving points and try and brute force it better
3. Live with it like it is.
I’m hoping there’s some technique I don’t know that reduces the time needed for option 2