Received from Charles this very interesting (and I suppose undocumented) tip:

array.highbyte[i << 1]=adresh
array.lowbyte[i << 1]=adresl

OR

array.highbyte[i * 2]=adresh
array.lowbyte[i * 2]=adresl

instead of

array.highbyte[i]=adresh
array.lowbyte[i]=adresl

Really interesting!
Ioannis