Legal Removal Request

Post: I took the time to search this topic before posting here for help, lots of great info to parse through.My project is to prototype a digital EICAS annunciator with LCD display. With up to 128 I/O.My first question is seeking recommendations or directions on how 4 IO Pi Plus expansion boards connect to one Raspberry Pi 3 B? Should I power each IO Pi Plus independently? I assume yes.The majority of signals are input only, with enough outputs to drive an LCD. If an input comes in, text is to display onto the LCD until it is manually cleared by a user.I've reviewed the video on how to assembly an IO PI plus board and see how the header connects to the GPIO. My assumption is these IO Pi Plus boards stack on top of each other and get chip selected via I2C address bits.Simple questions I suppose but would greatly appreciate an image or confirmation that this is the proper strategy. Also if there are any issues I should be aware of id appreciate any advice before buying parts.Thanks a bunch!