Aw, that's a shame - since reading about the Engineer suit in the Mobile Infantry Manual (RPG, of course), I'd tried to imagine how that might work. The main problem, of course, would be sufficiently differentiating them from regular Power Suit Platoons to give the exercise a point, whilst not simply making them better but the same.
If it were up to me, your standard Engineer/Trooper would have a D6+1 CC to reflect the increased strength of his suit, and perhaps bump the either Kill score or the Armour save up a notch. Nothing TOO earthshaking, like I said, but enough to matter.
As to their actual engineering ability, giving the Officers the Engineer (or Demolitions?) training for "free" and allowing squads a similar collective ability (just one trooper would manage little on his own, but a whole squad could do more than a single hero and faster?) and the ability to purchase specialized Emplacement assets (also usable by allied platoons, natch) - Trenchs? Bug/tank traps? Exploding boobytraps? Rigged terrain features? Pontoons and handholds for steep cliffs?
In terms of options and support, you could probably get rid of some (M9's and Hawkeyes; Sprites...? ) in return for the use of Thermo Charges like the Pathfinders have - or even bigger placed boomsticks like the famous TOADs?
As to the cadet platoons, I was a little disappointed to see those wind up as an adjunct to the Light Infantry when I had surmised them as an option for the Power Suits, similar to the Workers & Warriors option - Condensed Training, limited weapon and equipment options and such in return for a downgrade in price.
Of course, in practice, there's only so far SICON would be willing to compromise training and the whole point of being a CAP Trooper is the high level of training that is expected. Somehow I doubt the Mobile Infantry would stand for half-behinded cadets tromping about in expensive power suits or waving Javelins hither and yon. No, Mongoose probably went with the correct option there.
*ahem* Sorry, I seem to have wandered off point. What were we saying?