Atmega328P code on Atmega328PB

Hi all. I recently designed a board with the atmega328p as my MCU. Chip shortage is a problem and now can't get the 328P and if I do get it the price is 4 times the price of the 328PB.

I do not use a bootloader on my boards. I program the chip with the exported .hex file(without bootloader) using a ISP.

My question is if I make changes to the board and leave PIN3 and PIN6 unconnected, will my code work as is or will I need to make changes to the code for it to work.

Have you read this? AT15007: Differences between ATmega328/P and ATmega328PB

It's very important that you assign the right Arduino pin numbers to the chip pins.

Thanks. I think I am going to give it a go and see if it works.