Yep Wayne,
working almost vertically with modulars does mean that you cannot often get the angle to apply pressure and as you say the modulars lengths are often wrong. Sin of sins :

, Since the confinement of some of the 88ft job I have now cut down an old spare cracked extension to shorten it to about 3ft and also keep bits of the Zensorflex to do the same higher up the taper.
The brush angles change when vertical over pavements and in confined areas with handrails and barriers etc acting as an obstacle course when you have your head screwed right back, so I use brushes with soft splay, brushes with bristles at near vertical angles and use many and various angle adapters, one goes at 90 degrees over 14" cills when working vertical. At that angle you just sort of "feel" the glass and trying to find the bottom of the frame.
Yes the telescopics are better in the situations you describe. So I use the short section as above. I carry all my gear on the elecy golf trolley so the sections are at hand. I used to have the 8ft section Ergolites and in close confinement had to stand on steps to alter the height. Also appreciate that the facelift also comes into its own.
We need so much stuff now in our "arsenal"