What is needed to allow CG-Send-Binary for contests

Does I understand you right: similar to TS there is actually a tool available to transpile D coding to Javascript?

TS isn’t supported natively, so is D, but both can actually be transpiled.

Could you please send me the link to this tool? I want to try it out. Or do you mean, in theory someone can write such a tool? In this case mixing TS (tool available) and D (tool not available) seems not right.