This would make a great leader/ender project for those who do them.
SewSweetBee - Look @ this post from Bonnie Hunter's website. Scroll down to the 3rd quilt, a scrappy double Irish chain.
https://quiltville.blogspot.com/2005...-and-hows.html
She did hers as a leader/ender w/ 2" blocks. If you are using 2.5" blocks, disregard the measurements she gives and use the ones Jane gave in post #20 above. (Alternatively, if you have 2" blocks, you could follow Bonnie's.)
The reason I'm giving the link is that she explains that she is using 4 4-patch blocks, then what she refers to as "connectors" - 2 piece units with the light being the same as you are using in your alternate block and placed as Jane shows in post 20.
I don't know if I am helping you or making it more confusing... There are lots of very kind and helpful people here, so jump in and if you need help, just post. You'll get all the help you need here!