I am having the same dilemma.
My current BP is 2009 but unsure whether to spend £££ upgrading to 2018 as unsure how long that will last as worried standard will change again as 2018 is 6yrs ago
The 2009 was only ruled out in 2024, and as there isn’t anything other than the 2018 at the moment, it should be fine for a good few years. (You should replace them every 5 years anyway). I don’t imagine they will do away with the 2018 until some years after the next standard is made. The BETA website is good for info!