I agree with Chandra, it seems strange that putting softweave on a Mortimer of London Suit should provide significanly more "benefit" than an Armor Jacket or even SWAT armor suit or Milspec.
For example, given a completely average Human (All Attributes 3)
An Armor Jacket is 8/6, softweave would reduce this to being considered 5/6 for encumbrance (good)
SWAT armor is 12/10, softweave would reduce this to being considered 9/10 for encumbrance (-2 penalty)
Light Military grade is 12/10, softweave would reduce this to being considered 9/10 for encumbrance (only -1 penalty because of the Body x 3 for encumbrance)
Now the Mortimer of London clothing would not normally encumber a person with 3 Body, with the Suit Jacket, the full set is 5/3 armor.
With Option 1, the softweave would be reduced to 0/3 (or possibly 1/2)
Options 2 & 3 would both reduce this to a more reasonable 2/3 (Option 2 by reducing the Suit Jacket, Option 3 by comparing the total values and reducing the total 5/3)
Using Option 1 on the full SecureTech set results in the set providing its 2/6 armor for only 2/0 for encumbrance purposes, and that would only require a Strength of 1.
The game is set up such that having a low Body is bad. That's just the way it is. If you feel that you need more armor, there are plenty of ways to improve things without resorting to munchkin'ing your armor sets.