But in text frames it must not become impossible to type straight quotes as minute / second marks!
Well, if we are really nit-picking, minute and second marks should be U+2032 and U+2033, not straight single and double quotes 
Generally, I’m fine with smart quotes. For leading apostrophes I use Florian’s workaround with the letter before. The problem is that smartness is quite a relative thing. No matter in which language I work, I only get “English” quotes. What about «Swiss», »German« or « French » quotes? It works well if you enter the ASCII code (ALT+0171 etc.) into the popover. But for me that’s not yet smart! I say this with all the respect that we still are on version 2.2.20 (on a extremely high level!) and not, say, version 8 of Dorico. But I think one day the feature might be reworked – and why not add an option to switch the smart quotes off?
Right you are Rob. 
Maybe when they rework the feature for Dorico 8 they can add some smartness for proper minute marks, too. Along with a tool that automatically converts the duration of any given flow from minutes to kilogram and inches and any other SI unit – with correct typographic solutions for the unit marks, of course.
I hate it when people use ˚ when they mean º.
Quotes used in Finnish:
”Hyvää päivää!”
’Öylättiä, sanoi karhu.’
»Tokkopa tuota tohtinnoo…»
I’m not a big fan of smart quotes anywhere, but I understand the desire to help use correct typographical items. I think Microsoft is the main culprit in bad typography… For example their standard finnish keyboard layout doesn’t allow even some finnish letters! 
I suppose the correct reference tool could be polyglossia used in XeLaTeX — very nice tool if you need to have different languages with their correct typographic rules in the same document… But I would not know if it is possible to use such a tool to make Dorico better.
This “feature” also screws up Florian Kretlow’s wonderful Figurato font. He uses an “un-smart” apostrophe to give you, for instance, a crossed 4. The fact that Dorico won’t let you turn off smart quotes in lyrics disables this glyph completely.
I don’t think it’s appropriate to put the word feature in inverted commas, since it certainly is a feature.
I’m pretty sure he updated the Figurato Mac .otf so you can use “+” in place of “'”. Have you tried it?
wconable, are you on Windows or on Mac?
I’ve added support for curly quotes to Figurato and FiguratoB to mitigate this problem quite a while ago. Even if Dorico replaces the straight quote, the ligature should work nonetheless. Are you using the latest version?
FiguratoMac does not contain any ligatures with quotes, but Leo’s right: you should be able to get a crossed four with 4+.
Unfortunately there’s currently no proper documentation about the combinations that work in FiguratoMac and those that don’t.
Thanks, 4+ works perfectly.