Is it possible to register old version of wavelab Elements (8) with the code of new version (11)?

I just bought Wavelab Elements 11 Retail license, but my Mac is too old to install it properly (Mac OS not compatible, no way to upgrade). Is it possible to install old, compatible version of Wavelab (Wavelab 8 Elements) and use the code I purchased (Wavelab 11 Elements)?

Any new activation of WaveLab Elements will be on Steinberg Licensing, which only works with WaveLab 11.1 or later.

Recent posts in the forum are suggesting that Steinberg Support are refusing requests for new eLicenser activations, even in situations like yours when a downgrade is needed for compatibility reasons. That said, I would contact Steinberg Support to ask if there is any chance of an eLicenser activation.