I've cranked her to 50.50 with major tweaking, even modding non-weight engineering for random -% mass effects.
The dual SRV bay is definitely a load (18t... it kills) but it's one I carry gladly for my own reasons.
https://i.imgur.com/G7kOFxu.png
The two bay SRV is 10T (2G), just 4T extra from the 6T-one bay. Why 18T?