So, I used instant deconstruction on a small forward outpost I made, that had the towers place around it, only for everything to be removed except the towers. I tried to manually pick them up, but mousing over them doesn't highlight them. I can't destroy them, even with multiple M.I.R.V. & Orbital Ion Cannon strikes. Not even a hundred nuclear atrillery shells took them out.

Reloading my save, and trying to remove them by hand this time, worked. I turned off instand deconstruction and tired to remove them with bots, and it worked.

Just wanted to let you know. If you have Instant Deconstruction on, and tried to remove them with bots, that will not go away, and will be irremovable.

Everything else works great! Loving all you mods!

Thanks for reporting.
A pickup tower actually has two entities: a selectable one for the storage part, and a hidden one for the radar part (trigger item scanning and collection).
When the selectable one gets player-removed/bot-removed/destroyed, I have event script to remove the hidden one as well.
But for some coarse removal scripts, they may evade my scripts AND do not cleanly remove all entities, which caused the hidden one to remain. This is the cause of the glitch.

I will investigate what I can do to "catch" this kind of exceptions too. But since I am not experienced with scripting, I cannot promise if I can solve this.

PS: Factorio scripting is powerful to do many things not achievable by just prototype declarations. But they are also the source of many bugs and incompatibilities (like this case) of many mods. So tried to avoid them unless it is necessary for a worthy feature. :-)

I think you nailed it. :D
It's not a serious bug, as it does not cause a crash or anything.
I just need to remove them in a safe way.
Kinda like how I need to remember if I have regular or atomic rockets in my rocket launcher. ;)

Also, any chance on a Mk3? I have a number of turret mods installed with some turrets having a range that exceeds the Mk2 towers pickup zone. I think the turrets have a range of 80. (Plasma Turret Mk5). I would love a Mk3 with a range of say, maybe 128? If not, no worries. :)

Yes, actually I was thinking of the need of tier 3 (radius 96 tiles = 3 chunks), since the poison rocket in my another mod seems to kill things beyond 64 tiles. Maybe I can add both tier 3 & 4 (radius 128 tiles = 4 chunks) in one go, if some crazy weaponry mod really goes to such long range. :-D

Yet still, I would recommend using the lowest tier tower that can catch all loots near turrets, because of UPS concern. The pickup function is using entity searching, which will take long processing time if area (and number of items on ground) is too large/many.
Maybe I will tune down the power consumption of tier 1 tower to "encourage" players using that. (Tier 2 tower not changed.) The new tier 3 & 4 towers will take much more than double of the lower tier, for balancing.

That sounds really good to me! :D
I had to disable the Alien Ore, because with a high or very high bitter spawn rate, as I tend to play with, (I like War. ;) ) causes a absolute ton of ore to be dropped. I mean like, several hundred thousand ore. And trying to pick up that much ore causes my fps/ups to tank anyway.
Even with a tweaked loot pickup range of 64, it tends to take me 10-20 minutes to walk around and pick it all up.
It didn't really help to lower the loot settings to their lowest. But compared to vanilla Factorio, playing with your mods is way to much fun to be bothered by a drop in frames every once in a while.

Just released 0.17.3.
There are several changes, including: catching the script-based destroy events for clean removal, addition of tier 3 and 4 towers. You have to go into mod options to allow tier 3 and 4 towers though. (Default: 2)
I have increase the scaling in pickup interval and energy consumption though, to encouraging use of low tier towers for quicker pickup; against high tier towers for wider area.
Tier IV tower has pickup interval 240 s / 4 min, so you may need to deploy multiple (despite high power need) if you really have that many loots on ground.