hmm as a rulebook organisation thing, had you thought of putting the applied science tech trees under the theoretical tech trees they are unlocked by?
ie
Have the physics tech tree
then have Engine Tech, Laser Tech, Inertial Compensators, Shield Tech, FTL Tech, Power Tech and Fission Tech
then
Chemistry
with Armour, Mineral Improvement
though it gets a trifle more complex with applied sciences like Mineral Improvement which has requirements of Chemistry and Geophysics.
It would assist with making prerequisites more obvious