Originally Posted by Morelock

Loaded questions in here... I'll try to break it down

First the question of it being aero. The answer is... maybe. I've looked at a good number of guys lately who have jumped on the HUUB Wattbike train... and after some field testing, for most of them it's worse. Angling the arms is very hit or miss (you can read back 10-15 years John Cobb did a lot of testing mantis positions) the angle usually needs to be "right." What is right? No way to know but test... I have seen massive differences between a couple of degrees though. Also, in general (not always) going "mantis" is better at low yaw and worse at yaw. Inside a velodrome, that's usually a net positive as the angles are always very low. Outside, it can be pretty windy on the track. I say all that but at the end of the day... I can only tell you it can be a good amount faster, but when it's bad, it's often VERY bad. I would say the best "eyeball" judge is to see if it drops your shoulders (narrows them) and your head. At the end of the day for all aero fit, that's almost always the thing that will help. If your head pops up, it's no good. (again, broad strokes, not always)

As for the technical side of the question... you can raise just the pads with any spacers (so long as the bottom/top is flat - 3T spacers have little nibs on the bottom of them you'd have to grind off) ebay usually has some no-name carbon ones (search aero risers or aero stack spacers) or the old vision ones (they should work) In a pinch, you could just buy some aluminum pipe a little bigger than the bolt and cut it to size and use it to space it out(basically what the new Giant TT bikes use) Angling the pads will net you a small amount of room as well

Position overall - I'd move the saddle back a bit. Maybe a 10mm spacer under the stem.