Thanks everyone for your help. I have just verified two ways to get my v91 files to be workable in v92 and also in the 3rd party silhouette studio cutting software!!
*Method 1 - Suggested by Karina
Open the v91 file in v92 and choose the first "physical" option (the one that says "choose if unsure" - mentions masks, etc)
The graphic scale is preserved. When ready for the cutting software use File Save As "Plain SVG". The file opens perfect in silhouette studio.
*Method 2 - Suggested by Jabier
Open the v91 file in v92 and choose "digital art" file option. Next use the Extensions Document DPI 96 to 90. Save.
SVG is correctly scaled in both softwares!
I think I will use Method 1 (though I don't understand the underlying changes.) because I DO end up saving a copy (not master) for the cutter machine anyway.
Thanks all! :D
If you developers want to add a "SVG 1.1" save as option for SVG and/or a DPI save option for SVG that would be great but my issue is solved as of the time being. I guess as long as "plain svg" keeps being plain. ;)
________________________________ From: Marc Jeanmougin <marc@...3062...> Sent: Thursday, August 24, 2017 4:46 PM To: inkscape-devel@lists.sourceforge.net Subject: Re: [Inkscape-devel] SVG in 92 and Phyisical Scale
both "physical output" conversions produce a valid svg file where the orange area occupies a 11"x8.5" space being the entire page
Oops, sorry, I was too fast on this one, actually the least recommended method ("accuracy of the physical unit size") does not appear to set a viewBox at all¹, so the size of stuff will depend on the UA
-- Mc
¹:wtf, why → I will investigate on that