Access older version downloads/loading two version on site at same time

I am currently running an older version of JUX Megamenu (package & module 3.1.4, plugin 3.0.3). It's working fine, although I think a couple of the fixes (z-index, etc) would fix some minor issues we are experiencing. However, we had to do extensive styling/js customization to make it work with our template (based on Joomlashack Wright 3.0). I would REALLY like to go to the newest version CSS-only (no more mootoools!! yay!), but I don't have to to rewrite all our customizations. With that said...

1. Can I get access to the older version of the JUX Megamenu (prior to current version which is CSS only?)
2. Is there a way I could install the newest verision (or the version just previous that could be set to js OR CSS?) alongside the currently installed version so I could test it on a different page? Unfortunately, I don't have a test environment I can utilize to do my testing, but I have some hidden pages that I use to test new templates/extensions.

Thanks!

Dear cbcneenah.
Thanks you for using product our,
Do You want to have version 3.1.4 of Megamenu?
You can give me your mail. I will send for you.
NOTE: Because version have many the problem with JS. We just update new version for them
Best Regards,
Huyen Tran

I'm sorry. Perhaps I wasn't clear. We already HAVE 3.1.4. It works OK, with occasional glitches that might be fixed with version 3.1.5, 3.2, 3.2.1, 3.2.2. However, I'd like to start testing the latest version (3.2.3no JS), but I do not have a test site, and I had to customize my JS files and my CSS files to make my current site work with MegaMenu. You can see the menu here: https://cbcneenah.org

Is it possible to install and run 3.1.4 and 3.2.3 on a site at the same time? That way I could test the new no-JS version on a hidden page and update my CSS/JS files before rolling out the system live. If it is not possible, do you have any idea (after looking at how we customized JSE 3.1.4 on our site) how much work it is going to take to update to the no-JS 3.2.3 version?

Thanks!

Dear cbcneenah.
You can't install 2 module megamenu in 1 site. Because If you install version 3.2.3, old version will lost.
You can test version 3.2.3 in localhost or other site
Best Regards,
Huyen Tran