It looks like it has nothing to do with the booster, it is actually the Ships “passive bonus” that is not included into those green +stats. like if you have a berserker that have +30 thermal passive, put it into a hangar slot that has no implants and no booster - you will see that it will not show +30 for thermal resists on Hull.
I went through resits and speed boosters they all properly shown with green numbers on a ship stat windows.
So this is Not a Bug
[NB]
If there is anything else regarding boosters that is not working or suspecting to not work, please make a separate, proper, report.