Some people are very passionate about this idea of feeding in the enclosure and I am sure you will get a long explanation from a few that believe in it strongly and that it is bad for the snake to move it. In the end, I feel like it makes little difference. I will tell you of my personal experience though as I think that there is very little conclusive evidence on the subject.
Personally, until I had 10 snakes, I fed in a separate enclosure every time. The only reason I changed was for purposes of clean up. I had several happy healthy snakes that fed in a separate enclosure for years. When I decided to change over I found two things. First of all, some of my snakes were so trained to have a feed response based on being put in a separate container as opposed to the lid opening, that they WOULD NOT EVEN EAT in their own enclosure the first few times with a mouse in front of them, but when I put them in the container 30 seconds later, they would strike right away. That is how great their feeding response had been trained. I thought it was fantastic. I also saw, upon switching to feeding in their enclosure, on the negative side, that my snakes really do look up differently when I go to take them out normally. They have that feeding look rather than being indifferent. I have not yet been tagged, but I think it is directly associated. On another note, I have tamed some mean snakes which had been fed in the same enclosure all the time, and I believe that feeding them in another enclosure was key in calming them down.
On a side note, I remember watching a BHB video online wherein Brian spoke about the aggression of some of his snakes and how it was because they fed them all in their own enclosure. I just thought that to be very interesting. (BHB is a huge ball python breeding company and Brian is the owner).
Yes, forceps are popular to keep your hands out of the way.
Hope that is helpful.