Chosen Solution

I am using A1989. Is it possible to replace it with a 1708 display? Is it impossible because I have a T2 chip? I want to use a new A1706 display

What you want and what works are very different! No! You can’t use the older display used in either the two or four port 2016/17 models in the newer system. They are not compatible! Here is the correct part for your system: 13” MacBook Pro Display Assembly - Space Grey, Apple P/N 661-10037 (18/19 models)13” MacBook Pro Display Assembly - Silver, Apple P/N 661-10357 (18/19 models) Presently there is no used displays available which would be cheaper.

how about A1707 2 port with A1706 4 port?