Hostile Mob Spawning Mechanics.

[plasticpenguin]

So i have created a hostile mob farm in the forest dungeon. I have made 4, 15x17 "kill chambers" in all four cardinal directions, at around 23 to 38 tiles away from a central spot where i will stand while spawning occurs.

The kill chambers use two opposing rows of 15 arrow traps, which i will eventually upgrade to fire or void when i get the resources.

One of the chambers i put over what appears to be a mini graveyard biome as these seem to exclusively spawn vampires and i wanted the bat wings.

I'm using The Holy Rail mod along with the vanilla wiring and gates to automate the collection of drops.

The basic idea is that i have a rail that passes through every kill chamber once before returning to the centre spot, i have used a combination of timer gates and counters to essentially turn the lights on every 16 minutes and send me in the cart around the track, equipped with a magnet trinket.

Every 16 minute cycle seems to net me around 1200 bat wings and roughly a few hundred of copper, iron and gold ore each.

I wanted to do some optimisation and had some questions about the spawning mechanics.

-It appears to me that mobs don't spawn differently on some floor tiles and not at all on others. Is this purely based on the floor tile type or is there some kind of biome dependency? (I didn't want to tear up the graveyard floor to test this in case it is tile dependent and then i won't be able to get them back.) Also, if i use tile bombs to get rid of the floor it leaves a sand like texture, can mobs spawn on this?

-I have noticed there is a limit for the drops that will hang around on the floor before being deleted. If i run my farm in a 20 minute cycle or 24 minute cycle, there doesn't appear to effect how many drops i get each run. Is this dependent on time or amount of drops?

-The previous question made me wonder about spawn limits too, I imagined there would be a limit to the number of hostile mobs able to spawn and i have lit up as much of the surrounding areas as i can to limit spawns anywhere other than in my "kill chambers". Does anyone have any idea what these limits are? I was thinking i could optimise by increasing the spawn area in a 22 - 38 radius around the player essentially creating a circular kill room around the player, but not sure if a limit on spawns would diminish the returns on this effort?

-Does anyone know more about the spawning rules for the passive miners that you can recruit. They seem to be mega suicidal and often the first thing they do after spawning is head right into one of the kill chambers to die, which is fine but it clogs my inventory faster with iron swords. When they aren't trying to kill themselves they insist on coming to me and bumping me in the minecart which has sometimes put me out of sensor range and turned the farm off.

Anyway, i've really enjoyed working through this little project and the problem solving, i just wanna see if i can push it a little further before i call it done. I love the gates and wiring system and it has given me some ideas for more stuff to do in the future if more automation content is added to the game. Any ideas for optimising or automation would also be welcome :)

Thanks :)