Development / trend ages separate?

[slisajacobson]

I'm working on a project involving both premium and loss triangles. For the premium triangles, I'm using the TrendConstant method. In that case, the development field represents the trending date - but it's a bit imprecise because I can have a case where I develop premium to a different date than I trend/onlevel it to. I don't know if there's been any thought on providing options to split those? I am also new to chainladder so may not know if that distinction is already available, or if this really isn't the intended use of the package.

Thanks!