Network info doesn't serve any useful purpose on most vehicle projectiles. In fact it will cause problems. For example, if the plane dies and it's wreck is removed from the map (the timing of this depends on the vehicle's timeToLiveAfterDeath and the altitude where it died) it could end up with bombs "vanishing" mid-air and never causing damage to it's target.
This is because projectiles are automatically tracked by the server to start with. Added netcode is used to alter how projectiles behave in relation to ammo count (the size the mag command is set to in this case) and the status of the player that spawned it. For example on landmines, network info serves to limit how many projectiles that person can place on the map at any one point. If you rem out the network code, the first thing you'll notice is that you can then place an unlimited amount of mines on the map since then the server no longer tracks how many the player placed. Only their position and their owner is tracked.
Network info is also used on exppacks (aka C4) to allow the detonator to function on it (in conjunction with the limit on how many you can place). If you remove net code from C4, the detonator would cease to work in multiplayer.
That's really the only purpose it has and I would advise against using netcode on other projectiles that don't fit the two above circumstances as you are then only increasing the network overhead of your vehicle(s) and increase the chance of having problems.
Also if you ever decide to use the "isSticky" command, never use it on a projectile with network info added. Unlike BF Vietnam, the command is a little buggy. If used on a networked projectile, game CTDs will occur if the player that placed it dies and their kit vanishes or if they die in a vehicle before the projectile detonates. (I can't recall if server crashes occur in multiplayer or if just the client crashes, but I do know that it causes client CTDs in singleplayers) Another crash could occur on sticky networked projectiles if the object the projectile is stuck to vanishes from the map before it explodes. For example it gets stickied to a vehicle wreck and the wreck vanishes before it explodes or it gets stuck to a object spawned from an effect and is set vanishes from the map. Though this is impossible to occur in multiplayer since wreck effects aren't tracked fully in multiplayer, so the projectile likely can't stick to them since server side, the wreck particles don't exist. (only client side are they visible)
Netcode or not, never create a situation where a sticky projectile can stick to a dropped kit. Most mods won't have to worry about this since usually the mesh the kit uses when it's on the map doesn't have a collision mesh (since it's typically not needed), but if you have one that you enabled mobile physics on and gave it a collision mesh, the game will CTD (and in multiplayer the server will crash with same error) about a "Unknown kit part" error when the projectile attempts to stick to it. That's because the game "addTemplates" the projectile to the object it sticks to and kits have a specific set of allowed child object types and projectiles aren't one of them. (this also explains why sticky projectiles won't stick to the terrain since the heightmap system is hardcoded to never allow child objects on the terrain object) However don't worry about this occurring on kits currently active on a player. Once a player picks up a kit, the mesh you saw when it was on the map is deactivated and whatever collision mesh it had isn't included in any physics calculations.
Which explains some odd quirks like how sticky projectiles can cause the host object to move. When projectile stick to a vehicle, whatever momentum/speed the projectile had prior will be transferred to the host object causing it to move. Thus, don't make fast moving things like bullets have sticky or else you get hilarious results like vehicles vanishing into the sky at super sonic speeds.
So the only unfortunate thing about this is you can't have sticky C4 and still have it function like C4 due to the lack of network info.
The sticky TNT in my BFH'42 mod is timed and doesn't rely on remote detonation. Landmines can have it just fine, but without the netcode, that means allowing players to place unlimited amounts of them on the map as long as they have way of replenishing their ammo and they'll remain on the map even if the player dies.
Another very interesting quirk I noticed is that normally sticky projectiles can't stick to soldiers because since the 1.4 patch (or an older patch prior, I don't recall exactly when this was patched out) projectiles aren't normally allowed to physically interact with the soldier object aside from dieing on contact. If the projectile isn't set in the damage system to die from hitting a soldier (a landmine or C4 for example) then the soldier will pass through it and won't effect the movement of the soldier or the projectile. But I noticed one rare exception. My sticky TNT in BFH'42 when aimed carefully can still stick to a soldier but only if he's in a vehicle seat! Once he gets out, the sticky TNT remains stuck to him and he lugs it around with him until it explodes. I have a sticky vehicle landmine that might remain on the soldier for longer periods. I had fun sticking them to bots while they were in a vehicle. For some reason the host vehicle won't set off the mine, but it will explode if another vehicle gets close (which can also occur while the soldier is on foot) I basically converted that bot into a walking landmine. Quite interesting indeed.
Long story short, remove the network info, it's not needed.
