The TO revolves around the SR Companion and Shadowtech which, as far as I can tell, are both valid in SR2 and SR3.
The Allergy Flaw is basically open to brutally being abused. Just take a Mild Allergy to "everything" and get a pile of Flaw "points" that you can then spend on Edges. What Edges you might ask? Well for starters; all of them. A severe allergy to Uranium? Sounds good to me! A severe allergy to Arsenic? Bring on the free points! Repeat for an arbitrary amount of elements on the periodic table, most of which kill you anyways if you were exposed to them. Mild Allergy only gives you a penalty of 1 to your rolls (basically) and is barely noticeable so pick that as well.
Yes, your character has a penalty all the time you're not in your bio-suit, but this is SR, you can easily get a really badass bio-suit and never have a penalty. Also, who cares? You now can take several Edges that make you ridiculous, the best two are State of the Art Model at 6 value, and, Magical Talent, but you can also take an Arbitrary amount of Aptitude Edges that would cancel out your penalty of 1 if you were not in your badass bio-suit.
Also you have *all* Edges. So you have Friends in High Places and so on. You have an arbitrary number of additional contacts; *all* the Edges and an infinite number of Edges that you can take multiple times.
Now if you're a spellcaster, you've already won with Pun-Pun level ridiculousness at the starting gate. With an arbitrary amount of points from Magical Talent, you have all spells as an "innate" ability at Force 5 which is not bad at all.
If you're not a spellcaster, you want to open up Shadowtech and take a look at the "second hand bioware" rules (I know there are rules for second hand cyberware also but my books are packed and I can't seem to recall where they were printed.) When paired up with State of the Art Model, you can start with all Beta/Delta grade second hand wares for a fraction of normal essence/body index. With just a little bit of work I made a starting character who had 3d6+28 Initiative when his Adrenal Pump was *not* engaged; and I'm sure it could be improved. I recall another nifty piece of optimization where I combined the Synaptic Accelerator with the Move By Wire System; both list a ton of things that boost inititative that are incompatible with each item...but the items don't mention each other so...massive initiative!
With starting stats of 1 in Strength and Charisma, I still ended up with modified Strength of 7 and Charisma of 3 due to the sheer amounts of stuff this opens up. Highly TO and obviously not allowed at any table because you would be a monster from someone's nightmares. If Cybermancy were allowed at start, you could exceed this even easier, but I left that out because that would make it too easy.