Movie Studio 14 Platinum
Movie Studio 13 Platinum
Vegas

this is the original screen shot
above , is the original screen shot

this is Multiply blend mode ( everything is darker )
pixel example : .8 * .8 =to .64 ( darker )

this is Screen blend mode ( everything is lighter )
the equation for Screen blend mode is ( 'A * 'B )'
that is to say : Top Event is Inverted , Bottom Event is Inverted ,
then multiply ( Top * Bottom ) ,... next , that whole thing is Inverted via ( Parent Track Invert )
( "NOT A" multiply "NOT B" ) NOT
using 3 FX Effect Invert , and 1 multiply blend mode
i applied Invert to each "Event" to ensure , Top and Bottom Events are Pre-composite .
only the Parent Track uses Post-composite Invert .
Also notice ,
NOT on the Left side , implies "Pre-composite"
NOT on the Right side , implies "Post-composite"
( ) NOT , this "NOT" is on the Right side of Everything , thus , the FX Effect Invert ,
on the Parent Track is Post-composite .
again , FX Effect "Invert" is the "NOT"\complement operation .
( 'A * 'B ) ' is Boolean algebra .

extra note :
'A is "Invert A" pre-composite
'B is "Invert B" pre-composite
now we Multiply A with B .
next , that whole result is "Inverted" ( post-composite )

normally , with Boolean algebra , we would not be concerned with
pre-post composite of "Invert"\complement .
but here , with the video editor , we need to be aware and use pre-post correctly .

shows Invert , being applied to Top Event
in the same way , "Invert" , is applied to the Bottom Event
by applying FX Effect "Invert" , direclty to each Event\clip , ensures
"Invert" is applied as Pre-composite

this is the Parent Track , showing FX Effect Invert
note the Invert on the Parent Track is "Post Composite" , thus
( 'A * 'B ) has Fully composited ,...then the Parent Track will "Invert" that whole thing .


additional blend modes can NOT be made ,
because per-pixel crunch must be performed ,
and there are no FX Effect to do per-pixel crunch .

to get ALL blend modes :
go Vegas ,
go Photoshop Elements or CS
go Hitfilm Pro 2017