tl;dr

Types	RTS Opts	Compile time	Artifacts size
Yes	-A512M -H128M -n8m	3m7s	91M
Yes	-s	6m14s	93M
No	-A512M -H128M -n8m	1m22s	13M

For the last one I removed all type declarations apart from our main function. I also had to remove a few files as I kept running into an issue with the type inference algorithm of elm-make: Unable to generalize a type variable, it is unranked.

cloc

$ cloc .
     325 text files.
     324 unique files.                                          
      25 files ignored.

github.com/AlDanial/cloc v 1.76  T=1.05 s (284.6 files/s, 158321.8 lines/s)
-------------------------------------------------------------------------------
Language                     files          blank        comment           code
-------------------------------------------------------------------------------
JavaScript                       2              5              8         118011
Elm                            198           6549            708          22933
CSS                             16            372             80           6680
Sass                            55            743             66           5384
HTML                            12            351              2           2971
LESS                            17             61             67           1896
-------------------------------------------------------------------------------
SUM:                           300           8081            931         157875
-------------------------------------------------------------------------------

With +RTS -A512M -H128M -n8m -RTS, 3m7s, 91M build artifacts

$  rm -r elm-stuff && elm-package install --yes
Starting downloads...

  ● NoRedInk/elm-decode-pipeline 3.0.0
  ● Zinggi/elm-webgl-math 1.0.6
  ● alpacaaa/elm-date-distance 1.1.0
  ● Skinney/murmur3 2.0.6
  ● avh4/elm-fifo 1.0.3
  ● elm-community/dict-extra 2.3.0
  ● elm-community/intdict 2.1.0
  ● elm-community/graph 4.1.0
  ● elm-community/list-extra 6.1.0
  ● elm-community/string-extra 1.4.0
  ● elm-lang/animation-frame 1.0.1
  ● elm-lang/core 5.1.1
  ● elm-lang/http 1.0.0
  ● elm-lang/html 2.0.0
  ● elm-lang/dom 1.1.1
  ● elm-lang/mouse 1.0.1
  ● elm-lang/navigation 2.1.0
  ● elm-lang/svg 2.0.0
  ● elm-lang/virtual-dom 2.0.4
  ● elm-lang/trampoline 1.0.1
  ● elm-lang/window 1.0.1
  ● elm-tools/parser 2.0.1
  ● elm-tools/parser-primitives 1.0.0
  ● eskimoblood/elm-color-extra 5.1.0
  ● evancz/url-parser 2.0.1
  ● folkertdev/elm-deque 2.0.0
  ● folkertdev/one-true-path-experiment 3.0.2
  ● folkertdev/svg-path-lowlevel 1.0.1
  ● fredcy/elm-parseint 2.0.0
  ● justinmimbs/elm-date-extra 2.1.1
  ● klaftertief/elm-heatmap 1.0.0
  ● jweir/elm-iso8601 3.0.2
  ● krisajenkins/elm-exts 27.4.0
  ● krisajenkins/remotedata 4.4.0
  ● mdgriffith/elm-style-animation 3.5.5
  ● mgold/elm-geojson 2.0.0
  ● mdgriffith/style-elements 4.3.0
  ● opensolid/geometry 2.1.0
  ● gampleman/elm-visualization 1.6.1
  ● supermario/elm-countries 1.0.2
  ● rtfeldman/hex 1.0.0

Packages configured successfully!

$ time elm-make +RTS -A512M -H128M -n8m -RTS src/elm/Main.elm --output /dev/null
Success! Compiled 447 modules.                                      
Successfully generated /dev/null

real	3m7.904s
user	4m5.909s
sys	0m43.891s

$ du -h elm-stuff/build-artifacts/0.18.0/foo/bar/
 91M	elm-stuff/build-artifacts/0.18.0/foo/bar//1.0.0
 91M	elm-stuff/build-artifacts/0.18.0/foo/bar/

With +RTS -s -RTS, 6m14s , 93M build artifacts

$ rm -r elm-stuff && elm-package install --yes
Starting downloads...

# (same packages...)

Packages configured successfully!

$ time elm-make +RTS -s -RTS src/elm/Main.elm --output /dev/null
Success! Compiled 447 modules.                                      
Successfully generated /dev/null
 242,122,653,200 bytes allocated in the heap
 181,639,551,480 bytes copied during GC
     718,209,888 bytes maximum residency (1003 sample(s))
      20,109,768 bytes maximum slop
            1978 MB total memory in use (0 MB lost due to fragmentation)

                                     Tot time (elapsed)  Avg pause  Max pause
  Gen  0     461437 colls, 461436 par   944.174s  204.093s     0.0004s    0.0784s
  Gen  1      1003 colls,  1003 par   216.620s  36.564s     0.0365s    0.5996s

  Parallel GC work balance: 8.37% (serial 0%, perfect 100%)

  TASKS: 18 (1 bound, 17 peak workers (17 total), using -N8)

  SPARKS: 0 (0 converted, 0 overflowed, 0 dud, 0 GC'd, 0 fizzled)

  INIT    time    0.001s  (  0.001s elapsed)
  MUT     time  213.269s  (133.163s elapsed)
  GC      time  1160.794s  (240.657s elapsed)
  EXIT    time    0.000s  (  0.000s elapsed)
  Total   time  1374.066s  (373.822s elapsed)

  Alloc rate    1,135,291,776 bytes per MUT second

  Productivity  15.5% of total user, 57.1% of total elapsed

gc_alloc_block_sync: 13854752
whitehole_spin: 0
gen[0].sync: 356
gen[1].sync: 9277665

real	6m14.021s
user	22m54.066s
sys	7m53.766s

$ du -h elm-stuff/build-artifacts/0.18.0/foo/bar/
 93M	elm-stuff/build-artifacts/0.18.0/foo/bar//1.0.0
 93M	elm-stuff/build-artifacts/0.18.0/foo/bar/

Types removed, with +RTS -A512M -H128M -n8m -RTS, 1m22s , 13M build artifacts

$  rm -r elm-stuff && elm-package install --yes
Starting downloads...

# (same packages...)

Packages configured successfully!

$ time elm-make +RTS -A512M -H128M -n8m -RTS src/elm/Main.elm --output /dev/null
Success! Compiled 443 modules.                                      
Successfully generated /dev/null

real	1m31.936s
user	1m22.255s
sys	0m11.761s

$ du -h elm-stuff/build-artifacts/0.18.0/foo/bar/
 13M	elm-stuff/build-artifacts/0.18.0/foo/bar//1.0.0
 13M	elm-stuff/build-artifacts/0.18.0/foo/bar/