I integrate both, as I want the LBB2 maneuver but the LBB5 toys and economics, and ships designed by both systems to 'play' together.
Many problems, but the biggest one was dealing with letter drive stepdown damage vs. value damage.
My solution was to go with a tonnage based damage system, predicated on the EP system for LBB5 black globe absorption. 1 EP of damage equals 10 tons.
Armor stops damage or allows pens. Pen based on comparing battery strength to armor, has to be higher number.
To hits are as per LBB5. Short range is 250,000km.
Battery strength for any sort of energy weapon drops 1 per 100,000km, which affects damage and to hit.
Missile pen is predicated on battery strength plus velocity. The higher the velocity the higher the pen potential and damage. To hit numbers are not affected, the base battery to hit remains the same (subject to computer power).
To hit increases +1 per 10,000 km lower then 100,000km, for both missile and energy weapons.
Damage tonnage is determined, divided in half and rolled depending on weapon type. Less then spinal weapons typically roll surface for the first damage and general for the second. Meson weapons get the first hit internal and the second general. Radiation hits follow the first hit, doubling damage if it can be hurt by rads (fuel is not destroyed but is considered unrefined), and second hit rolls separately.
PA Spinal and nuclear weapons are two general hits and two radiation hits (that means two shots at Critical, meson guns have internal hits first and that one is a 1d6 for critical instead of 2d6).
Critical hits are disable not destroyed.
One damage table based on the CT one, but with ranges that cover surface, internal and radiation hits.
Missile design redo is a big part of it, m-drive up to 10G by TL15 and missiles can carry their own computer model. I mitigate that quite a bit with a custom detect/lockon, but it was important to me to put in the economics of having to pay for those missiles especially bay ones.
Much more to it, but that's the basics.
Not everybody's cup of tea, but always the chance of stealing bits for people's own purposes.