Hmm, you should immediately see a lot of info, like here is what I get:
iex(devserver2@127.0.0.1)2> :etop.start()
========================================================================================
'devserver2@127.0.0.1' 21:11:05
Load: cpu 0 Memory: total 62468 binary 1427
procs 384 processes 24416 code 22299
runq 0 atom 1017 ets 2741
Pid Name or Initial Func Time Reds Memory MsgQ Current Function
----------------------------------------------------------------------------------------
<0.1027.0> 'Elixir.FileSystem.B '-'43147764 689568 0 gen_server:loop/7
<0.286.0> 'Elixir.Phoenix.Code '-'30204171 5692948 0 gen_server:loop/7
<0.9.0> erl_prim_loader '-'18242316 689524 0 erl_prim_loader:loop
<0.1040.0> 'Elixir.DBConnection '-'17875451 25164 0 gen_server:loop/7
<0.1026.0> phoenix_live_reload_ '-'11739249 42436 0 gen_server:loop/7
<0.277.0> cowboy_clock '-' 9445910 8932 0 gen_server:loop/7
<0.1.0> erts_code_purger '-' 7799639 44776 0 erts_code_purger:wai
<0.2.0> erts_literal_area_co '-' 6650619 2688 0 erts_literal_area_co
<0.1048.0> 'Elixir.DBConnection '-' 4554875 4176 0 erlang:hibernate/3
<0.1044.0> 'Elixir.DBConnection '-' 4494410 4176 0 erlang:hibernate/3
========================================================================================
Which keeps updating every few seconds (my dev server here is not under heavy use at all, or really any use). You have to kill your shell to stop it though so be careful not to kill your server instead, hence why remote shells are best. 
Just as an efficiency check, they are keeping an active TCP connection to the server to do that yes? Setting up and tearing down tons of HTTPS connections on Gateways does have a tendency to kill them pretty badly even though elixir handles it well.
