Cybran engineers/acus with T3 build suite have the ED4 shield available to them, which can be upgraded to ED5, but either one of them are awful.
Aeon 18k HP 2400 mass
UEF 17k HP 3300 mass
Sera 21k HP 3600 mass
Cybran 16.5k HP 4260 mass (or 13k HP 2460 mass)
This is either way too weak for its mass cost or way too expensive for its shield HP. To keep in line with cybran shielding being weaker (like in T2), I'd suggest making ED5 the main blueprint for T3 buildpower and reducing the build costs for ED5.
this is the simple solution, alternatively you could rework all of cybran shield's phases because as it stands now, upgrading them is a massive scam