I assume that with the new 32hrs TAF life has become easier?
Considering big airport in modern environment new TAF format helps. Flying to "particular" countries or airport the problem remains because very often there is NO way to find forecast on the sys until you are airborn.
For this reason EU-OPS says that you MUST select 2 destn altn when destn apt forecast are below minimums or no destn apt forecast are available.
Different legal tricks are already explained.
Moreover, as told, you can legally fill in a flight plan to the "alternate" considering the commercial destination as "alternate".
e.g. LHR to JFK, flight plan to BOS with JFK as alternate. Along the route decide where to fly.
Ciao