I do understand regarding the contact. When xSO and I were in more contact, I used to count three initiated contacts by him and then I would make a small one. (Three was random, but I find numbers very soothing).
So much depends on what you want - slam the door or keep it open a bit. Maybe it is selfish of me, but since I am so not ready for another relationship, in my case I can keep that door open without extra pain to me, so I keep it open.
At some point, Bright, if you want to indicate that the door is still open, you'll have to break out of your current pattern. That, I think is when you can send a small, personal joke or follow some of that advice in the Text Your Ex book that you once were kind enough to quote for me.
I know how scary doing something different can be. The business conversations are comfy territory. After several months of NC, I decided to send a short text to xSO. I was scared he would not answer and he never did. But as it turns out, his non-answer gave me an answer anyway.
When you are ready, Bright, I would encourage you to try. There is nothing to lose and everything to gain. You can always return to the status quo. We will be here for you, no matter the outcome. If it makes you feel better, feel free to run some ideas by us.