SUMMARY
As of version 25.04, the width of Jetbrains Mono Nerd Font is rendered incorrectly when enabling ligatures. I especially notice redundant space between words that contain escape sequences (basically the same error as in MR https://invent.kde.org/utilities/konsole/-/merge_requests/911).

STEPS TO REPRODUCE
1. Create a profile with Jetbrains Mono Nerd Font 10pt set as font.
2. Check 'Word mode' and 'ASCII characters' under `Appearance/Complex Text Layout` to enable ligatures.
3. Look at text that contains escape characters (colors in my case).

OBSERVED RESULT
Redundant space (see https://pasteboard.co/62dLW8ZzqtxL.png).

EXPECTED RESULT
No redundant space (see https://pasteboard.co/BxZkW04JYWFI.png).

SOFTWARE/OS VERSIONS
Operating System: NixOS 25.05
KDE Plasma Version: 6.3.4
KDE Frameworks Version: 6.13.0
Qt Version: 6.9.0
Kernel Version: 6.14.3 (64-bit)
Graphics Platform: Wayland
Processors: 22 × Intel® Core™ Ultra 7 155H
Memory: 30.8 GiB of RAM
Graphics Processor 1: Intel® Arc
Graphics Processor 2: NVIDIA RTX 500 Ada Generation Laptop GPU

ADDITIONAL INFORMATION
Looking through the commit history between the 24.11 and 24.05 releases, I found that https://invent.kde.org/utilities/konsole/-/commit/be76d4a2480fbf24e261cf3bf0f69a781100d534 may be the culprit. And indeed, a custom build that had this commit reverted behaved as expected.

Based on the message of the commit and aforementioned MR, it seems that there is one-size-fits-all solution. But what about exposing the hinting style as an option of a profile? Then you could tune the option to the chosen font.