With Elite : Harmless, in-flight rendering of the planet both before and after hyperspace draws extraneous straight lines inside the planet's circle. As the planet's size or position in the viewport changes, these lines are not erased and they accumulate until the whole screen gets garbled. Changing the viewport to e.g. back view and again to front view clears these lines momentarily, but the issue persists. Please see the images attached, taken from the real target system.

Does not reproduce with the original source on same build and target hardware.

Built from master at 1st of July on macOS Big Sur using cc65 V2.19 and Exomizer v3.0.2, tested on C64c & 1541, c64c & 1541Ultimate2+, and ultimate64. A friend of mine also tried a build with Debian from the same source on Commodore hardware, and has the exact same issue. Not tested on emulators.