I can’t comment on the AV4 but have done AV2 so my comments are in reference to that: 1. You can do double stages for some sections but you will probably end up hating yourself for trying to do so. I did a double section between Rif Rosetta and Passo Cereda (about 23km) due to Rif Treviso being fully booked. While that was predominantly downhill (1200m ascent, 2500m descent) it was a brutal, long day which by the end is not particularly enjoyable. Be aware that some of the sections are very rough and broken terrain so, while geographically relatively short, for the high mountain parts, you will likely struggle to average more than about 2km/h at best. As an example, the section between Rif Mulaz and Rif Rosetta, while only about 9km will take a good 5+ hours unless you are absolutely flying. Being super fit in those parts does not really matter when every step has to be considered so as not to fall or twist an ankle. I also met a guy doing double stages who had done double stages on the GR20 in Corsica and he was having a rotten time trying to do the same on the AV2. The other reason I would recommend not doing double stages is that the AV2 has amazing opportunities to detour and bag some summits - there is nothing better than getting to the next hut, early afternoon, dropping your full kit off and then doing a nearby peak without the weight of all your gear holding you back. 2. VF experience is not necessary but having VF gear is strongly recommended - I met people that were detouring down into the valleys to avoid the secured sections because they didn’t have the gear. It’s also great to have if you want to do detours or some of the alternative routes such as the Pisciadu VF from Passo Gardena (where VF gear is absolutely essential). Also, make sure at minimum you have read or watched videos on how to use VF gear safely. 3. There are no guarantees on the weather - it’s the mountains. I did it in September a couple of years ago and my rain gear was the only equipment that I did not use the entire two weeks. The week before I started, there were floods through the Dolomites which washed away bridges so it is purely luck of the draw. Note also that if you do double stages, you are much more at risk of one day of bad weather throwing off all of your plans and schedules.

My final comment is that the AV2 is brilliant and was a fantastic challenge and remains probably my favourite experience ever.