Old chunks appear to be "playing catchup"

Samsung Galaxy S3, only app running.

When a pre-existing chunk reloads at a view boundary, it frequently causes lag and oftentimes crashes MCPE. It maybe related to chunk updates on large maps when a chunk hasn't been accessed for awhile and contains active blocks like fire. I've noticed that when you move out of a fire area (I burn entire forests routinely for deforestation) and then reload some of those chunks, the fire effect rapidly catches up on the reloaded chunk. If you use fire as an ornament (ex. on Nether Rack for fireplaces or torches) this seems to cause these issues. I have entire cities with fireplaces, and the game will freeze every time I walk 16 blocks and a new set of chunks loads. Same issue did not occur on 0.10.x and earlier. My hypothesis is that the game engine is "catching up" with active effects like fire and possibly some entity movements tick for tick, causing long lag on large levels when areas are accessed that haven't been entered in some time. We know fire is intended to burn down a target, so when it's used on something like NetherRack and burns in isolation, these updates shouldn't be necessary. This will be a vital issue if you release the Nether on MCPE without fixing this problem.