One-handed (half-QWERTY) layout for physical keyboard connected to non-rooted Android device

My goal is to be able to use a physical keyboard (connected to a non-rooted Android 10+ device via Bluetooth) to input letters located on the right side of a QWERTY keyboard while actually pressing only keys on the left side. The solution could be specifically tailored for one-hand typing but a general key remapping solution might also work (it needs to allow the key to send one input when pressed alone and a different input when pressed together with a modifier key). Due to a hand injury, I am forced to temporarily type with only my left hand on the QWERTY keyboard. One way to improve the typing speed in such a case is to use software that enables a half-QWERTY layout for touch typing. The way it works is that when a letter (such as q) is typed with its usual hand, the operating system sees it as that letter, but when it is typed while holding a modifier key (e.g. space), the respective letter on the other end of the keyboard (the one typed with the same finger of the other hand in two-handed typing) is used by the operating system (in this case, p). For desktop operating systems, there are solutions allowing the implementation of such mechanisms (e.g. Karabiner-Elements on macOS, AutoHotkey on Windows) but I was not able to find such a solution for Android. It doesn't help that in the context of mobile devices, a one-handed layout is most commonly applicable to touchscreen keyboards, not physical ones, so searches for related keywords do not return any meaningful results. I would prefer a system-wide solution but for my use case, I mostly need it for code-server (version of VSCode accessed via web browser), Obsidian (note-taking app) and optionally Termux (terminal emulator for Android). I can remap keyboard shortcuts for these apps, so I am mostly concerned with regular typing (letters, special symbols), not key combinations. Also, I would use it mostly for Onyx Boox tablet (Android 10 device with epaper screen) but I also use other devices with the same or newer Android versions.