Firefox 51.0.1 with Geckodriver problem

Hello

I'm doing automated tests with a Selenium platform. We use Firefox Portable for browser sharing on a single VM. Until now, I used Firefox 46 and under in Portable Edition to do my tests, with Selenium 2.53 which doesn't require GeckoDriver.
Now, I wanna test new Firefox versions but Geckodriver is mandatory !

The problem is, the same code execution doesn't produce same result for Standard 51.0.1 and Portable 51.0.1. In the first case, I can reach a specified page. In the second case, a page is opened: file:///C:/Users/$USER/AppData/Local/Temp/rust_mozprofile.j9Pz8K5gSlQC/ and it freezes due to a bug in the driver. The real problem here is: Why does this page open up at startup ?

I talked about it in official Geckodriver Github: https://github.com/mozilla/geckodriver/issues/469
Maybe it's a problem of parameters --profile $(path to profile) and then Portable edition doesn't interpret it well and then opens up the profile instead of using it. Is it the case ?
They suggests me to move on standard edition but I wanna know if I can find a workaround with the portable edition.