Switch off the automatic lighboxification by UNticking Table IV-G5 and 5.1.
Manually add ( using the text editor ) to the <a> tags the argument:
data-rel="wppa[MySetname]"
MySetname may be anything, the images having the same setname wil be in one set. Example from my test site where i worked this out:
<a href="https://beta.opajaap.nl/wp-content/uploads/2015/12/gpstest-1.jpg" data-rel="wppa[MySet-1]"><img class="size-medium wp-image-6646" src="https://beta.opajaap.nl/wp-content/uploads/2015/12/gpstest-1-300x202.jpg" alt="Test" width="300" height="202" /></a>
<a href="https://beta.opajaap.nl/wp-content/uploads/2015/12/gpstest-2.jpg" data-rel="wppa[MySet-1]"><img class="alignnone size-medium wp-image-6647" src="https://beta.opajaap.nl/wp-content/uploads/2015/12/gpstest-2-300x200.jpg" alt="gpstest 2" width="300" height="200" /></a>
<a href="https://beta.opajaap.nl/wp-content/uploads/2013/01/56.jpg" data-rel="wppa[MySet-2]"><img class="size-medium wp-image-1321" src="https://beta.opajaap.nl/wp-content/uploads/2013/01/56-300x199.jpg" alt="Plaatje 2" width="300" height="199" /></a>
<a href="https://beta.opajaap.nl/wp-content/uploads/2015/12/gpstest-3.jpg" data-rel="wppa[MySet-2]"><img class="alignnone size-medium wp-image-6648" src="https://beta.opajaap.nl/wp-content/uploads/2015/12/gpstest-3-300x200.jpg" alt="gpstest 3" width="300" height="200" /></a>
You can see it here: https://beta.opajaap.nl/nl/ for a few hours.
The first two images are a set, and the second two also.
The only thing you miss is the hourglass cursor, but you can add that as well manually.
