Looks like goahead is not a good choice to replace LuCI.
It uses too much space(850KB), maybe memory cost is low, but flash cost is not acceptable.

Also it request librt.so and libpthread.so, that is about 100KB addition flash cost.

I think maybe write a real light weight one is the only choice. We do not need that complex cgi function, we just need a way to transfer data between browser and the server.
Currently vocore.io/store, the trace page is based on a light weight C language web application(I am not good at php, so have to write one in C), it will not be very hard if we just have a simple cgi and do not use https.

Ship will take about 5~40 days. If it takes very long, I suggest to use DHL/UPS/Fedex.
Alpha, average ship time(about 100 packages):

Position         Average Time    Note

Australia          8 days        (min 6, max 12)

Austria            10 days       No official data.

Belgium            12 days

Brazil             40 days

Bulgaria           14 days

Canada             14 days

Czech Republic     14 days

Denmark            11 days

Finland            14 days

France             10 days

Germany            15 days

Greece             26 days

Hungary            20 days

Israel             22 days

Italy              20 days

Netherlands        10 days

New Zealand        8 days

Norway             17 days

Poland             14 days

Russian Federation 21 days

Spain              36 days

Sweden             30 days

Switzerland        12 days

Taiwan             14 days

Thailand           9 days

Turkey             16 days

United Kingdom     7 days

United States      7 days    (min 4, max 14)

Japan              14 days

India              48 days   (min 34, max 70)

To US,UK and Asia the speed is acceptable, 90% packages are delivered in one week; To Europe countries, the speed is fair, about two weeks for most of them, but Spain, Greece, Sweden takes very long time… Even worse, to Brazil, it takes over a month, due to there is no air plane from China.ShenZhen to Brazil. Better to use DHL/UPS/Fedex if you want it get you fast.