Ok… Step 1 in the testing…
Buy the ship… ick… 3,150,000 credits kissed goodbye as ill never fly it… lol
Ok, Ship purchased… lets see now.
Buy Heavy plama… since i use mk3, but ill never use it, ill buy the mk2… even though the mk1 has the same projectile speed… ok…
Ok, with no weapon mod, I already have the implant you stated, it reads as 2860 m/s projectile speed.
Add mk2 supernova modifier to reduce by 56% and it reads as 1128 m/s… just as you said
Have an Mk3 supernova, so tested it, same thing 1128 m/s.
Removed the 30% jericho implant and its 978 now…
So… 56% reduction on 2200 is 968… not 978
Exact same thing happens when I put the same equipment on my cerberus 2.
Lets try a booster circuit… 2200 + 30% = 2860, so no issue with the implant.
Add booster curcuit… 2200 + 30% (660) + 54% (1188) = 4048… total listed is 4037
So yes, there seems to be a bug in relation to projectile speed weapon modifications but, not the jericho implant when it comes down to the heavy plasma as the same mods with hail plasma are true to the % values that they come to represent. It seems to hit the reductions alot harder than the bonus’s though.
I would test some more, but I already spent about 5 million credits on this test, and im broke now. I do have screenshots though if the need for them come up.
Short version
Tested heavy plasma for projectile issues
Multiple ships showed to have same issue
Hail plasma didnt show to have these issues
Jericho projectile speed not an issue
Weapon Modifications not an issue as they work as intended with hail plasma
ULTIMATE RESULT
Weapon modifications + heavy plasma = incorrect projectile speed weapon mods calculations
Ive forwarded a link to this thread to a dev, so after the weekend is over, we should hear something.