Yes, I do live in Europe.
There are already two sets of plans. Metric and Imperial.
I am afraid that giving too many details will only confuse people as to which set of plans they should use.
(And I mean newbies, novices and people wanting to start woodworking and DIY, not the people here. Most people here can copy my design, and probably any design, by just looking at a single picture.)
This is why I make my plans with the following distinction:
Imperial = for people in the USA and those in UK, Australia, etc, who prefer the Imperial system and have access to materials.
Metric = for everyone else who most probably do not have access to Imperial materials or when they hear "Imperial" they think of Ancient Rome or Emperor Palpatine.
Each one should make adjustments to fit their materials, it is nothing complicated, and I do provide the Metric or Imperial SketchUp file with the relative set of plans to play with.
In woodworking the tolerances are not very low anyway.
I do not make Woodworking Lesson Videos, but there are many kind gentlemen and ladies out there who do. Far better than reading a boring lesson in the form of an article, written by a non-native speaker.
What I might do, is make an article about the different types of plywood in the USA and hyperlink it into the PDFs along with a hyperlink to these forums and some other places.
If Metric plywood is closer to el cheapo plywood, then by all means, use the Metric plans but make adjustments when necessary.
There is a strong probability that the el cheapo plywood is made in China or Russia and it is not really undersized, but instead it is 18mm Metric that is sold as 3/4 Inch, (3/4 would actually be 19,05mm). They can save a lot of money by selling wood just 1mm thinner.
And my plans are FREE. You can download and use them for free for personal or commercial purposes.