While we're not rejecting it, I do have a guestion: what does the final tank skin look like? I see no pictures of it in the workshop.

I noticed that the parts of the tanks you retextured are also the ones that get rextured on the final tank skin (the grill and skirts). I realise that on most maps and missions a skin specificly for the last tank doesn't give the players really critical info that can be found otherwise.
But on a map like area 52 the final tank skin is used to tell the players wether or not the tank is going to capture the gate. Other custom missions sometimes also use the final tank skin to convey info other than "this is the last tank".

You might have misunderstood or misread Interrobang's comment (I've only found 1 in which he explicitly states "2 weeks") in which he said:
"You only have 2 weeks to get a halloween mission/map in ".
(And as is also stated in the comment, it's too late to get your new halloween map/mission in now with judging and reworking taking too long)

And has jakapoa has already said, they will remain in CC until the campaign ends.

You will not recieve another medal for reaching previously-reached thresholds again.

Teien has been known toi impact perfomance due to arguable over-detaling. While but I've personally not oft heard of metro and coastrock causing perfomance issues.
As for the problem of lag when looking in a specific direction, try disabling the skybox in the meantime.

Even if it leaves beta it'll stick around for quite a while. We don't have an official date to end the event on. the "deadline" is when community interest fades.

If you have any bugs, please post them in the bug-report thread with more details than this. Without any error message, server number, time of crash, possible mods/configs on your end, or the mission in question we can't do much about it or hope to recreate the supposed bug.

But if TF2 crashes than it has to be on your end, as every mission is tested for functionality and will not pass if not fully functional, and coastrock is a fully functional map and so are its missions. And even then, most non-functional missions don't result in client crashes, they result in the server crashing at worst.

I've done experimenting with colours and outlines, see my results here: https://imgur.com/Onba5tF

Went for solid black as it's very easy to see on both normal- and giant icon backgrounds. It also maintains a reasonbly sharp edge. in both Though I will experiment with colour, now I'm curcious.

Though don't count the recolour getting into the standarisation, admins are already set on using this version.

There, this medium has a white background

RIght click > view image OR view image info. Transparant background on imgur is black