Changes the merging in the deconstruction planner, so you can more easily find stuff, and have more fine grained deconstruction planner. Also increases the number of entity and tile filters you can have
It has several modes:

• Custom (the default): this uses a custom merging I created (things with very similar names/properties are merged, others are not). For example, rather than listing all three sizes of demolisher remains, it only lists 'Small demolisher remains', and dry/dead trees are separated from trees, as they have very different pollution absorption. Unfortunately I can't change the displayed name only for the deconstruction planner, so there's no 'Rail' option, only 'Straight rail' (which also deconstructs 'Curved rail').
• Vanilla Factorio: this doesn't alter the merging at all, allowing you to use the mod simply to change the number of filter slots
• Same Name: Merge things with the same name only (e.g. you can individually select 'Tree', or 'Brown Tree'). This only knows the English names from vanilla factorio + space age.
• None: Don't merge anything (e.g. you can individually select each of 10 different entities named 'Tree')
  The above only effect stuff in the environment tab, and rails (in the logistics tabs).

Note: Same-Name and None mode will unmerge anything added by mods, whereas the others will leave them intact.
If you want different behaviour for a specific mod, let me know!

Sadly the game engine doesn't let you merge tiles (e.g. you still have to manually select both directions of hazard concrete).

You can also change the number of filter slots (Vanilla factorio uses 30, the default for the mod is 100, and the maximum supported by factorio is 255).