A highlight like the sandbags so I can see where my trenches are going.

I dont think that its possible, but will check after i release 1.3

thanks for looking into it

Could you make tank traps, like the pits filled with water on the final German mission in the base game?

Making tank traps wouldnt be a problem, but the water is tricky, i know because i have worked with it and was a nightmare

I dont mind if there is no water, even just pits would be good, and maybe a bridge to cross them for creating choke points?

Will check after i finish 1.3 :)

I don't know how long it takes to build a trench. It could be too risky to build a trench line when the enemy attacks before it's ready.

Yup thats a balance in it, it takes 30s-20s to finish a long trench, smaller ones takes 10s max.
It woudnt be real to dig a large hole while enemy assaults you, you have to repel the attacks and defend a possition while the engineers finishes your trenches and bunkers.
Or you can dig trenches from a safe distance and slowly gain land while your safe trenches covering your attack

Cool, thanks!

Just turn it into large-scale Company of Heroes and add gun entrenchments like an uncrewed Flak 88?

It would be too op i think :D
You could spam flaks with cheap infantry equipment, but for cannons i have planned that i make some dank sandbag/wooden barricade which do shield them from artillery

Sandbags that you can connect together and make interesting shapes like you see in many of the singleplayer levels

Tank dig-ins, places to entrench tanks and whatnot. Might be a little on the powerful side, but make it a 3 min dig?