Piping sizes

[Throwaway543]

My pool runs 1.5" pipes from the pool to the equipment area. When the two skimmers connect, it is in a 2" T with bushings to bring it down to 1.5". Oddly, it then brings it back down to 1.5" before the 3-way with the main drain and remains that way (for the salt cell and heater). I have 3 return lines that do the opposite. They go from 1.5in, expand to 2", and then back down to 1.5" on the runs to the pool.

I am redoing the plumbing this spring and am wondering if it make sense to do as much as possible in 2" and instead just drop it down to 2" into the pump and from the pump to the filter which are both 1.5". From my understanding, this will make it a bit more efficient and give the added value being when I get a new pump/filter that I could easily make everything 2".

[Teapot]

Yes do it!