i think a little common sense goes a long way here, if you have a fixed blade that is sheathed and in your pack, which is not easily attained!... it shouldnt be considered if you where stopped and searched should this arise, once in the area where you intend to carry out your bushcraft activities, that doesnt mean the generic open to the public campsite, as whenever there is a general public incurrence there is usually a misunderstanding of some sort!... dont wear your shiney knife and fine leather sheath where it can be misconstrude as a wannabee 'Rambo' its bound to attract attention and unfortunately the wrong sort.
as for pocket knives, i use them all the time, i dont wander the streets with a great big lock knife in my pocket, if you sit in public and get your knife out your pocket to cut your apple in half, if its a big fancy lock jobby i think you might draw some attention, if you get your little knife discretely out and do the required i cant see an issue, obviously the blade needs to comply, and dont shout out at the top of your voice'Do you need that cutting in half' to your mate 20m away!
i think correct stowage has a lot to play in this area, if its easy to get at it, albeit to slice your apple or not, the powers that be will see it as a possibility to inflict..... and therefore you risk prosecution, like i said previously a little common sense is required, i am surrounded by sharp things most of the time, all stowed in and out of harms way, i carry a penknife for the little things that may be required and use it discretley as and when, once im out of site and in the realms of basecamp or wherever i will make the larger fixed blades available, lets face it in reality we dont usually need a knife strapped to our sides for emergency's here in the uk, if youre around camp or even yomping along, you dont need your fixed blade to hand.
all only my opinion, and no upsett intended.
Adam.
my EDC is an opinal No8, i keep it well out of site and i dont walk in the local pub with it in my pocket either, the only person ever damaged with it is ME! just thought i would mention.