Hi Brown Bear,
I'm an ex forester, both for the FC and private estates. It all depended on how you presented yourself with me, others I worked with generally had the same idea. If you looked like you were responsible and not about to either burn the place down or leave litter then I'd have a wee chat, swap ideas, point out good places for resources maybe even have a brew then leave you to have some fun. If you looked like trouble, were building a fire the size of a wicker man and were ****** I'd escort you to the boundaries and take note of your license plate.
You just need to look at some of the areas of the national parks and how the public abuse them. Loch Lomond and the surrounding area is a toilet... literally. One of the nearest lochs to me is Loch Earn. Here the estate has a pretty good policy despite having a wave of idiots there most weekends.
It's popular for fishing and they have a couple of rangers patrol the banks. When you set up camp they'll pop along ask if you're fishing ( you need a permit) and if not happily leave you alone with a request that you don't cut living wood or leave a mess. Heck the rangers even have bags of wood for sale in their van ( cheap too ) and a leaflet about not being an idiot. But still they have to prosecute folk for bringing chainsaws to cut trees for firewood, and rescue folk who get ****** and take boats out and then sink. The litter is unbelievable and most of these folk are fishermen and "bushcrafters" ala BG.
Sorry on my
there. ( the worst are the bloody "ramblers" ). I think you'll find most foresters / rangers pretty sympathetic to what you do - it's generally why they're there too. as long as they feel that a) your not going to cause trouble and b) be discrete and not trash the place.
Cheers
Goatboy.