Tremolo bars collide with ledger lines

For details see this thread:

https://musescore.org/en/node/140996#comment-600671

Procedure: Enter notes (crotchets or minims) with several ledger lines. Add tremolo bars.
Result: The tremolo bars will be on the ledger lines and make reading the pitch difficult.
Desired result: The tremolo bar should cross the stem inside the staff where they only cross staff lines.

Appendix: There are two additional minor problems with tremolo bars.
- They often are at the very end of the stems: The stem should always be visible on both sides of the tremolo bars.
- In beamed notes the tremolo bars often touch noteheads, beams, in some cases even both. The fix here would need to include moving the beam away from the notes by 1 - 1.5 spaces.