'His stride is two metres long' seems like the most natural way to say this to me.
I'm not sure anyone is even reading the reports on this course, let alone fixing errors.
They are. Every time the course contributors accept one of my suggestions, I get an email about it.
I can assure you they do. You will only get a reply if your report is accepted. To expect a reply to all invalid reports is just too much to demand.
Reporting definitely helps, but can take awhile. I have kept all my replies to accepted answers, over the years, for different languages. I probably have 20 that have become accepted answers. So the system does work.
The singular is also "skridt". Had the singular version been used here the only difference would have been in the last word. I.e. "Hans skridt er to meter langt". And it might be worth noting that "skridt" also means "crotch" which gives the singular version a potential, albeit slightly nonsensical, double meaning.
"His pace is two metres long" is how we say it in the U.K., but rejected by Duo. Meters is from U.S.A., and metres is U.K. A meter in the U.K. is a measuring device. When we talk about the length of our step, we say the length of our pace. Have reported.