Hi Carlos,
Great month for me: just because of the SCN, and besides all my travels, I was able to look directly at Italian and Guatemaltec personalization. In your case, to discover that, as you said, the option is unavailable.
So, from my cursus as SAP, long years ago: perhaps trying to find a personalization which does what you want (meaning, including the BSP) and from your language.
In all cases, open a bug (or feature request) to SAP.
What I would try, at least for the fun of testing 
is creating a different DB with a fully different personnalisation (French, Dutch, whatever, but which is using the BSP) and looking ta which value in the DB is changing and manually activating it in a Guat. DB.
For sure not supported, but for the knowledge and the fun of it will be interesting.
Will try after my diner.
From my point, if the option is unavailable it will not work with the SDK.
Regards,
Eric