Hi Ignacio,
the solution to avoid 9.1.4 is as shown below (following the description of SNote 1669003):
Example: FX1031- using a Posting Spec like:
40
F9.1.3 Technical position clearing
Other G/L posting in payment currency
50
F3 Suspense Account
Other G/L posting in payment currency
Result: no posting on the intermediate account linked to Account Symbol 9.1.4. 
Best regards,
Lorenz