Programming/gaming monitor recommendations

I'm a work from home software engineer, I spend most of the day at my desk staring at my dual monitor setup. There are some specs I'd like to upgrade based off what I've read online, but I want to hear if any tildes users have strong opinions about the hardware.

My primary display is a Dell S2719DGF (1440 144hz), and my secondary display is a Dell P2719H (1080 60hz). My primary display is for programming & gaming, and I want to upgrade to 4k 144hz. My secondary display is my primary display for work, only used for programming. I want to upgrade it to at least 1440, maybe 4k if it's as good as they say. I also need 100x100mm vesa mount support, though I think most monitors have that these days.

A few points that I'm not certain about:

• I've read that 4k is better for reading and writing code because the higher pixel density makes text sharper. I definitely prefer 1440 over 1080, but is the jump from 1440 to 4k as noticeable? I've never used a 4k monitor.

• My current primary display has a low response time. I don't play fast-paced PvP games anymore, is this something I can give up and not notice?

• I think IPS panels are the move for both displays, for better contrast and to avoid burn-in, but I'm no longer well educated on the current landscape of panels. MiniLED? QLED? QD-LED? What'sNextLED??

• Both of my displays are 27 inches. I'm hesitant to upgrade to something larger like 32 inches and lose pixel density. Is the difference between 4k@27in and 4k@32in negligible?

• I just moved my office into a loft with poor lighting. I read that dark rooms require better contrast but I'm not sure what good or poor contrast looks like.

• Is my fps going to take a hit from increasing the resolution of my secondary display? I don't know if there's a lot of extra overhead from the increased resolution. AMD GPU/Gnome/Wayland btw.

If you're a programmer/gamer with a hill to die on regarding monitors please share it with me!