See videos. First video sign use classic TRDOS rom and classic ZX roms:
And this is same video with fixed TRDOS version:
This ZIP file contain different ZX roms and TR-DOS roms with fixed return to basic:
1) - Fixed ZX rom refresh value of HL' register after return from machine code. This roms ignore bug in all trdos versions and RETURN will work always correct with all trdos roms.
2) - Fixed TR-DOS roms refresh HL' register before return to ZX rom/basic. Can be used with all ZX roms. (this way is best )