/3/ - 3DCG

Hey guys I need some pointing in the right direction with node shit.
I'm making a little skyscraper generator, that I can hopefully, by the end of it, gen a bunch of different skyscrapers with different bases, middles, and tops.
In simple terms, I'm basically just recreating the array modifier, but using the start and end cap settings as well.
I'd like it to work with different dimensions of the parts (maybe the base is short/tall, or I have some different floor heights), which is where I'm hitting a bit of a snag.

I have it somewhat working, in that I can offset the floors and top based on the base's height, but I'm running into an issue where the floors don't match up unless I use specific values for the original curve's Z length. Ideally, it'd just resample the curve based on the height of the floors, and put them seamlessly on top of each other, but as you can see there's gaps. Probably because the points don't fit comfortably within the length of the curve, but I'm not sure exactly how to fix it.

At the end I'd like to randomly influence the height of the buildings (which for some reason I can't do because the random value node doesn't plug into the line curve end vector), and if the values aren't matching up to whatever value its expecting I'm gonna have gaps.
Anyone know what I'm doing wrong?

Here's a catbox link to the file in case you don't want to try recreating it yourself.
https://files.catbox.moe/g5ruyd.blend