According to the wiki:

Forbidden Exosuit Modules grant at least two to a maximum of four of the following six bonuses:

• 📷Shield Strength: increases the durability of the Exosuit's shield.
• 📷Core Health: adds 1 health square (the player initially has 3 health squares).
• 📷Life Support Tanks: increases Life Support capacity
• 📷Solar Panel Power: during the day, reduces the Life Support drain of all movement functions
• 📷Sprint Distance: Sprint bonus: increases maximum sprint duration
• 📷Fuel Efficiency: Jetpack bonus: decreases Jetpack's drain on Life Support

My thoughts on these are:

• More shield/health is always good as a buffer
• Bigger tanks increase the time between recharges but then again fuel is cheap and plentiful
• Does the drain reduction from solar panels really help?
• I use the jetpack to gain distance and only rely on sprinting when the jetpack is recharging
• I'm not sure I should bother with fuel efficiency as a) I have bigger tanks from the above bonus and b) ultimately, fuel is cheap and plentiful

What do you prioritise when choosing upgrades and what is your reasoning?