The battle dress in the core and the CSC are both frankly under armoured anyway, i believe that some time ago on one of these thread, Matthew himself suggested adding two points to the value of battle dress (making the core examples 18 and 20 points). Using the vehicle book rules for building power armour, you can make suits with much more armour for less then the 3 or so million for battle dress in the MRB (i built one that had 24 points of armour for just over 2 million).
I think the CSC AP rules are poorly thought out, and the new armour rules in that book for layering are also poor. A simple solution might be to allow such armours as TL10 cloth, protect suits and diplomatic vests to be worn under armour with no penalty, which is a cheap way to give you a bit more armour and protection (+3, 4 or 5 extra points).
The tech level thing is a bit misleading as well, AP rounds for TL8 or less personal weapons, ok, but DSAP for a modern assault rifle (TL7-8) not sure those exist. Also, a bolt action rifle of WW2 penetrates modern body armour (Lee Enfield No 4 for example), so one of those penetrating TL8-10 armour not so much a stretch, especially if provided with AP or some how DSAP.
Higher tech weapons, well lasers can be protected from by ablative armour, or the oddly described reflec armour (which is assume does not actually reflect the laser bolt, but scatters it) which is an option for many types of armour, Gauss rifles are meant to be for punching through heavy armours like TL14+ combat armour and even battle dress to some extent. And for the big boys, like PGMP, better to be in a TL14+ tank, or no where near some one wielding such a weapon
