As promised from the previous post: Equations.
First let's start with an equation describing the relative velocities between normal space and subspace.
Where K is the constant of about 8.24x10^23 kg^-1m^2. v_n is the velocity relative to all influential gravitational bodies, depending on the precision needed. The more precise this needs to be the more bodies need to be considered, such as for sensitive instruments going into subspace to observe anomalies. If it is an emergency or the computer power is limited, which in this time period would probably mean there was also other emergencies, less n bodies can be used. Of course if the right bodies aren't considered it can be catastrophic in when a wrong exit point is determined.
The second equation calculates the "depth" that the system will enter into subspace, or the potential energy.
Where G is the gravitational constant, m is the masses of objects and d is the distance from those masses. With further posts I will give further equations on depth, but essentially this is the potential energy of the system and can be modified for the benefit or detriment of ships in subspace.
I think this is all about geeking out over playing with numbers. And setting up equations which I can throw real numbers into to see what happens.