Over on the continent of Europe the manufacturer GIOS os held in very high repute, possibly on the same level as De Rosa, but without the Eddy Merckx connection.
As far as I recall the "Compacr model had a specially desgned pair of adjustable rear drop-outs, that enabled the rear-end stay ength to be shortened bi about 1.5 cms ( or somrthing of that order) taking it from a 40cms to around 38.5cms , a measurement which in Europe is reckoned to be the shortest that it feasible if the frame is not to become skittish and unpredicable..for road racing terms. I have not heard of any peculiarities of head angles.. and would assume that on a 56 cms frame the angle would be no more than 73.3 or at an extreme 74. However a steep head angle does not always lead to odd steering... and some of Merckx' frames have had 75 haed angle, on reasonably small frames combined with a pronounced fork rake... to help offset the effect of the Belgian pave.
The compact rear end is not really a fairly modern innovation as a similar type of adjustment was available on the French Automoto frames in the 29 and 30s.
Norris Lockley.. from a very steamy and sweaty Settle UK