Dear @imetamorphic first of all welcome to the club.
Secondly we dont need threads to conclude that steermatic's running on CNG will eventually start getting problems with transmission , your below post is enough to prove, in which you are getting engine malfunction light.
No offence with my brothers running their steermatic's on CNG , but the heart of steermatic is its CVT transmission which is synchronized with dual transmission & 7-speed manual mode , now when you install CNG the sensors which are like arteries taking blood to the heart, will get disturbed because they sense and respond best on liquid fuel , when you press your accelerator the sensors will pick the amount of mixture of fuel & air and that sensing system eventually give signals to CVT transmission by which you enjoy L15a VTEC engine of steermatic in D , S or 7-Speed M-mode.
By installing CNg some times you will not fully enjoy the synchronization of all these sensors & eventually CVT transmission get confused , which leads to other problems.
Red Lady is Running on Petrol , so hope fully people running steermatic on CNG can guide you & give better tips that how you can avoid problems.