i would have preferred:

    templ<thing>(a, b)

because with that:

    templ!thing(a, b)

is it a function?, or are you calling thing's function?

you can do:

    templ!(thing)(a, b)

but did you mean?:

    templ!(thing(a, b))()

i personally always use !(), no matter what, and it's annoying to type, i don't want to waste time constantly trying to figure out what is what, it's mentally draining