The Perfect Layout plug-in can automatically extend slurs on tied notes until the end note (see image 1).

Image 1a (Left): Original; 1b (Right): Slur Extension

Case 1b) is standard notation in most cases. Exceptions which should not be extended are for example string staves with very many tied notes or guitar staves where the legato slur might be mixed up with a hammer-on/pull-off slur. These exceptions are deactivated by default.
Notes tied over many measures or with many ties should not be extended either. The default maximum span is three measures or three ties (Option: "Only If Tied Measure Span and Number of Ties is Less or Equal than X Measures").
The plug-in removes 'open' ties (i.e. ties not connected to an end notes, also called 'l.v.' ties) by default unless they belong to an instrument that actually can play 'l.v.' (e.g. harp, cymbals, glockenspiel, etc.).

Image 2a (Left): Original; 2b (Right): Open Tie Removed
To visually emphasize the middle of the bar, Perfect Layout re-ties notes which cross the middle of the bar by default unless there are symbols (articulations, expressions, hairpins, etc.) assigned to the removed measure position which would then become invalid or unclear (e.g. measure 3 in image 3).
There is also the option to only re-tie notes if the first tied note starts after beat 1 (activated by default).
In odd time signatures (e.g. 5/4) there will be no re-tieing.
Note: Perfect Layout never adds extra notes. This means: not all cases of falsely tied notes are corrected (e.g. measure 5 in image 3).

Image 3: The re-tie settings of Perfect Layout
m.1: Only re-tied if "...After Beat 1" is deactivated
m.2: Always re-tied by Perfect Layout
m.3: Never re-tied by Perfect Layout because otherwiese the hairpin on beat 4 would become unclear.
m.4: Always re-tied by Perfect Layout
m.5: Never re-tied by Perfect Layout because otherwiese the hairpin on beat 4 would become unclear.
Glissandi are aligned horizontally and vertically to not collide with notes, note dots and/or accidentals.
Usually glissandi are note-attached smartshapes or tab slides.
By selecting "Handle Solid Lines as Glissando" or "Handle Dashed Lines As Glissando" it's also possible to use measure-attached smartshapes as glissandi.
As this option is unselected by default, it's not available in the Silver edition.

Note: If selected, the algorithm currently assumes that all solid and/or dashed lines are glissandi. So use with caution.
Otherwise for example dashed crescendo lines might be turned into a vertical glissando line.
Trill lines, brackets, ottava lines and custom smart lines that include the hidden keyword "PUTONTOP" are taken into account for vertical collision removal above the staff (not below!).

Perfect Layout (starting with version 3.x/Gold edition only) offers three options for setting the SmartShape distance above the staff:
a) Distance to the Top Staff Line: 25 EVPU by default
b) Distance to the Top Staff Line on 1-Line Staves: 58 EVPU
c) Distance to the Top Note Symbol: 23 EVPU

The keyword "PUTONTOP" can be added to any of the five text fields (Left Start, Left Continuation, etc.) in the Smart Line Designer dialog. Just type in the word (no spaces), then select it and apply the hidden text style (Text->Style->Hidden).
The smart line then might look like in image 3 (dependent on the text fields that you select): no more collision with the tuplet bracket and the slur.

Image 4: Custom Smart Line with Hidden "PUTONTOP" Text

Image 5: "PUTONTOP" in the text dialog

JW Lua cannot read the fields from the Line Adjustments group in the Smart Line Designer dialog.
Workaround: If possible, don't use these values, as they may lead to collisions.