I am puzzled by the 'half inch over depth bit'.
For reasons known only to themselves but partly due to their upturned mouths, crucians actually go past vertical to feed. Imagine one of those big crucians 10 degrees past vertical. Its body is pushes the line and bait out of the way. For this reason the crucian experts of Ringood, and they've been catching them for more than thirty years reckon that two to three inches overdepth is much better than dead depth or even just an inch. Bear in mind the bottom is far from table top flat anyway (especially in the Ringwood gravel pits that have loose flints everywhere) and the extra couple of inches makes all the difference.
I wish we could fish 0.09 - we use 0.16 - 0.18 but then our bonus fish include big tench and double figure carp. Never found them that hook shy either; a 16 or 14 is OK. As for shy bites, Neil Maidment will confirm that when we fished Witley Park, early on the bites were the usual tiny dithers but if you could really get them feeding, and many did, the bites turned into rapid, easy to hit, sailaways. I just wih I could remember how we got them really feeding, could have been sticky-mag?
Fishing with Neil last week on Todber manor I caught crucians fishing in a weed bed; the bottom was covered in dead reeds yet I got crucians on punched meat amongst the muck.
Gold fish feed differently, only feeding at an angle that is well short of vertical.