I can confirm that the rcf now works in 0.91.8 as intented. There are no errors anymore and bubboblr1 loads fine.
Sadly I have discovered another issue, which I think is only kind of a forgotten debug flag or something: Every output from the cli is redirected to stdout.txt instead of the real stdout, so I cannot redirect stdout to my own file and append the output. This is how I tested -rc for all files. I guess this is easy to fix, but as everything seems to work fine now, there is no need to hurry
Thank you so much, great work.