I have a question about the following from the change notes:
"- Fighter complements are now tech-sensitive. Once you research all the base units in a single tech level and advance, ships in the previous tech level will receive improved hangar complements, often with new fighter/bomber designs."

How exactly does this work? Do I have to research all ships (to include all fighter designs) or just freighters and above? Does it matter if I research a single type of fighter to the max? What happens if I max out a ship before researching everything in the tier? If I only research the ships I want/use, will this ever trigger or will each ship only have its' default complement until I research everything?