In the UK, can you just take out your plane at your uncontrolled airfield and decide to go up penetrating clouds in airspace G? Without having filed an IFR flight plan and without the goal of flying IFR?
Yep and if you don't speak to anyone nobody will know you have done it.
You can also do the yo-yo between IFR and VFR if you like as well.
Or pitch up out side CAS and request a IFR arrival if you so wish. Be you VFR or IFR without a plan up until that point.
The only time you need a flightplan in the UK is if you want to use the airways system or cross an international FIR or you are over 5700kg.
The ATS in class G though is very strange as well. I wonder if that !!!!e will be put to bed as well with EASA?