Thanks for the "heads up" about this. I'm just getting into Java for some iText work with PDFs generated from Notes docs, and still feel a bit uneasy about how some of suchlike thongs work in the Eclipse-based Domino Designer (not only for Java).
As well as a few counter-intuitive things like the one you've mentioned, some things are a step or two further removed than they were on the old Designer. A trivial but still irritating example of the latter is that you have to click on a button to launch the Workspace Icon Editor, rather than simply double-clicking the item in the navigator in the left column.
In a similar vein (about Designer 8.5.x annoyances), is that for years I've copied icon images from those shared databases of dozens or hundreds of Notes workspace icons, then pasted them directly into the icon editor matrix. But with the Eclipse-based IDE this doesn't seem to work any more, which is quite annoying.
I've discovered a workaround: I paste the icon into the icon editor of Domino Designer 7.0.3 working under Windows 7 XP Mode (virtualised), and find that then I can copy the icon matrix from there across into the 8.5.x icon editor running natively under Windows 7.
While I agree wholeheartedly with everybody else that the Designer for 8.5.1 is a huge advancement, I get the feeling at times that such rough edges have arisen from the dreaded "committee consensus" way of deciding things, rather than being signed off by daily practitioners [like us] who need everything to operate ultra-efficiently without superfluous steps. But then, I'm just an out-of-touch old grump approaching the end of forty years in the game, so who am I to criticise!