Even with regeming, I dont think you're geared enough to make the swap to softcapping ArP yet. Maybe with 2-3 more key upgrades you mentioned you're farming for,you will have enough ArP on your gear to do so. The softcap with NES is somewhere around 722 Armor Pen. So before you regem from Str to Armor Pen make sure you can hit that with gems + food.
This is my understanding. Softcapping is easy once you have mostly 245 gear, and then hardcapping becomes viable once you're in mostly 264 gear with a mix of 251, as long as you pick up the right pieces of gear.Or do you just softcap until you know you can hardcap, and thus hardcap it instead?