I built a plow about 35 years ago for my pickup, being too poor at the time to go store bought. I used a 12 volt winch to raise and lower it, with a rudimentary manual angle change. I ran into the exact same issue, when angling it, and all these years I thought it was my poor design, glad to see a "real" plow with the same issue! I eventually learned how to make it work, that is I didn't make any structural changes in the plow, just learned to work around it, solid frozen ground solves a lot of any issues.
Fast forward to the present, my brand new QA 6' blade from Attachments Direct (their Minnesota location, built locally "we know snow", sold me, plus the guy I talked to on the phone, on a Saturday no less, knew his snow plows and sold me, shipping it out the next day. I did cheap out, telling myself simpler is better, and did NOT go with a hyd. angler, just manual. I don't have a cab, so I'm wearing a snowmobile suit when I plow and blow anyway, plus my property layout is such that multiple angle changes aren't needed. I of course had to try it out, at least put it on, not enough snow yet to mess with, and noted the very same angle issue, bringing back memories of my homebuilt one! One big difference: now I can roll the bucket up or down, plus I have easily adjustable skids, have a proper spring overload/kickback system,on top of that I'll wait until winter really hits and it's all rock solid, no problemo.
I still have my 5' ProTech snow pusher (unless I sell it locally, been trying, $400.00) and as this winter progresses it will interesting to see how I mix and match the FEL bucket, the new blade, and the pusher. I'm above 5,000', near a ski area, with lots of wind, so it's a fairly serious business, all gravel driveway.
