All of those ideas sound great, dubia is a very easy species the only thing about them is you have to be patient.
If you are proactive in removing un eaten food items, with as many as you have you may only have to clean once every 4-6 months. The frass they will produce is not a bad thing to have. once it starts to get 1 to 2 inches deep is when it becomes time to clean. If it becomes to damp in your bin or starts to smell, it will be a good time to clean as well. the substrate should be relatively dry at all times. it is good to scan your bin for dead roaches from time to time as well, picking out all the dead which shouldnt be very many. Nothing like crickets. I clean all my bins once every two weeks but then again i have 10s of thousands per bin. The frass can pile up very quickly haha. Good for fertilizer though.
You didnt derail this thread. the whole purpose behind this thread is to provide the best information for breeding this amazing feeder insect. Not only food items are important, temps, humidity and husbandry are all equally important. If you have questions ask away my friend.