Browsing through the forum 14 also seems somewhat problematic (eg with Google Maps - no idea if that had been fixed) and people recommend against using it.
So let me rephrase the question: what does 17 have that might make B4 want to move to it, or is there no practical difference to 11?
After all, if I understand it correctly, B4 is a wrapper for JDK that uses the BASIC syntax and therefore a subset of the capabilities (note to self: check whether you can include Java code). Would any of those capabilities be affected by the move to 17?