Whenever it is necessary to play five sixteenth notes on one beat:

• Temporarily increase the tempo by a factor of 1.25 (5/4) by inserting a new metronome marking before and after the pentuplet where the second one is the original tempo.  Select each tempo marking and Cntl/E to not display them.
  
• The pentuplet is entered as ordinary 16th notes. Select the five notes and click on the Beam icon. A "5" can be inserted as a text comment over the middle note.
  
• Notes played concurrently with the pentuplet need to be tied to an equal note with 1/4 the value of the original.
  
• To properly display these concurrent notes, it will be necessary to create a displayed but muted staff while hiding the original staff. Click on the + icon to create a new staff then return to the staff you need to copy. Press Home, then Shift/End to select everything on the staff, copy it to the clipboard, select the new staff, and paste it.
  
• Where you have extended the length of a note by a quarter, remove the tie on the original note and change the note which now follows it to a rest and hide it. Notes can be beamed even if there are rests between them.
  
• Hide the original, played, non-pentuplet staff by selecting "Page Setup" from the File menu or the "open book" icon. Under the "Contents" tab, uncheck that staff listed in "Visible Parts.
  
• Steps 3-6 need to be repeated for each staff with notes played concurrently with pentuplets. Where another part contains a rest on that beat, a hidden 16th rest will need to be added at the end of that beat or measure.  If another part has a measure rest, a one measure hidden time signature with an extra 16th would work: e.g., if in 3/4 time, create and hide time signatures of 13/16 and 3/4 before and after the pentuplet measure.
  
• If you plan to use the tool: Audit Bar Lines, it would be necessary to insert the hidden before and after time signatures on all staves.

When playing a triplet concurrently you can beam the notes being played with the hidden rests as above.  It will be necessary to include the final rest when you reselect the triplet to be tripletized again.  The bracket which indicates what is in the triplet will be a little long at the right end, but that can't be helped.

The attached file is an example. pentuple

A discussion of other n-tuples is in N-tuples (vs m-tuples).  Also, Triplets v. Duples, 3/4 v. 9/8, Hiding "3" in triplets.