You realize that "alpha" is less stable than "beta", right? Extremely experimental version. I thought you might already know that, so I mention it just in case.
But I thought you wanted to try 1.0 alpha to find out if the new LPE is in it? Is it?
Measure Path is available in the current stable version (where it should be working without errors, afaik). But it only gives you the text. It's not the complete solution that you want. However, there's probably a way to create a somewhat streamlined process, if you wanted to try a compromise. For example, I'm thinking maybe a custom document template might offer some possibilities. Or a 2 step process, with the Dimensioning extension plus Measure Path. Or maybe other routine?
Isn't there a way, using the Measurement tool, to turn the measurement marks into objects? I think there is. I'm not very familiar with that tool, and find it confusing and hard to use. But with some research, it might be possible this would work. Fortunately there is some instructional material on it. Find the Inkscape article in this issue of Full Circle magazine. I haven't read this one, but it's from a very good series!
http://fullcirclemagazine.org/issue-121/Moini, is there any beta version currently? Or is all the new work going into 1.0 alpha?