Small fixes

[keurfonluu]

• Fixed: allow more than 5 USERX values.
• Fixed: force a white space after the end of TIMBC block (it seems that it is required despite the user guide saying otherwise).

Reminders:

• [x] Run invoke format to make sure the code follows the style guide,
• [x] Add tests for new features or tests that would have caught the bug that you're fixing,
• [x] Write detailed docstrings for all functions, classes and/or methods,
• [x] If adding new functionality, unit test it and add it to the documentation.

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

Project coverage is 90.21%. Comparing base (00363f6) to head (ff69fc5). Report is 14 commits behind head on master.

Additional details and impacted files

```diff @@ Coverage Diff @@ ## master #166 +/- ## ========================================== - Coverage 90.21% 90.21% -0.01% ========================================== Files 97 97 Lines 6284 6283 -1 ========================================== - Hits 5669 5668 -1 Misses 615 615 ```

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