Compose: Proper way of extending the RowScope Modifier? (Or any Scope Modifier for that matter) - kotlin

Question

I'm creating a Row of Text Composables, imagine it like a table row.
Image: https://i.stack.imgur.com/jR3oB.png
If you care for the backstory:
The amount of "cells" of my custom Row Composable is dynamic and I use Box Composables to wrap the Text in the "cells". I need to apply different Modifier parameters to each Box, which I first tried to achieve via creating a Modifier extension.
Code of my Modifier extension:
#SuppressLint("ComposableModifierFactory", "ModifierFactoryExtensionFunction") // I wish I could. The RowScope requirement makes doing it the easy way impossible
#Composable
fun RowScope.rowOfTextCellsBoxModifier(
index: Int,
columnWidths: ArrayList<Dp?>,
columnWeights: ArrayList<Float?>
): Modifier {
#Suppress("RedundantExplicitType") // bull**** (compose kotlinCompilerExtensionVersion 1.3.2)
var returnModifier: Modifier = Modifier
if (index != columnWidths.size - 1)
returnModifier = returnModifier.then(Modifier.verticalEndLine())
returnModifier = if (columnWidths[index] != null)
returnModifier.then(Modifier.width(columnWidths[index]!!))
else {
val weight = try {
columnWeights[index]
} catch (ignored: Throwable) {
1f
}
returnModifier.then(Modifier.weight(weight!!))
}
return returnModifier
}
I moved on to just generating the entire Box in a #Composable function, but that's beside the point ;)
As you can see, I want to add a Modifier.weight() at one point.
However, .weight() is a Modifier function that is only applicable in certain Scopes, like in RowScope. Which means that my "Modifier extension" needs to apply to RowScope, which turned out impossible to find instructions on.
So, imagine I hadn't found a better solution:
What would be the proper way of extending the RowScope Interface's Modifier?
Usually, when you need to create a Composable that is applicable to certain scopes, you write something like:
RowScope.YourComposable() {...}
And when you extend Modifier, you write:
Modifier.yourExtension() {...}
But that does not work for Scoped Modifiers:
RowScope.Modifier.YourModifierExtension() {...}
is invalid code.