just opened one WN2000RPT v2, the chip is as same as WNR2000, and I successfully loaded dd-wrt., so I believe loading openwrt should not be a problem.
but, the real problem is: there is NO wan port on WN2000RPT, which means you will not get WAN connected.
if you want keep going, two parts are required:
- one 10/100 base-t single port isolation transformer module
FPE H20201DL-R, https://datasheetspdf.com/pdf-file/1373471/FPE/H20202DL-R/1 - RJ45 sockets with PCB mounting post
then some soldering works.