Great game, very fun acually, continue what you are doing. I had some free time and I did this the max amont of logs floating in the air :)
to be hoenst I used this strategy to cheese some of the challenges cause the "reach 2/s" an such challenges only look at how many items are burned in a given time.
so if you steadily harvest each one and dump it, one after anotjer.
or just collect 100 in a pile and then delete a slate to dump them alla t once into the fire dowesnt matter.which aenugh planning and collecting, you may be able to cheese the "keep >2/s for 15 sec" things too.
jsut collect a ton of things in a container.and then open a slit that is chosen in a way that just enough of them roll into the fire at once to keep the needed frequency going.