Like Stan we made our gravel pad larger than the unit. we mixed our gravel with Bris (crusher fines) as well, it helps the gravel to pack better. We still use a weight distributing pad under the front jacks but have a concrete pad for the rear jacks i think in time I may pour a small pad for the front jacks as well and leave the gravel for the rest. I would also note it would be a lot easier if it was all concrete as working under the unit in the gravel can be tedious however gravel cost a lot less.
1997 ford f-250 ps
2019 Volante 240RL