I'm not sure about others but after my full riding season of 2020 I found that the MTT Damper was no longer silent and I got some squeaking noises, for lack of a better word, coming from the MTT damper area. I followed the BMC MTT Service and Maintenance Manual (attached to this post - English version) and inspected the serviceable parts and realized that my Guide Shafts simply needed a lube. Luckily they weren't worn as to need replacement.
Point of post is that it is a relatively easy task to accomplish and personally think it's a good idea to do once a year regardless. Make sure you have a decent torque wrench since the shafts need a precise 8Nm of torque so as not to result in premature wear of MTT parts and/or possible frame damage.
Point of post is that it is a relatively easy task to accomplish and personally think it's a good idea to do once a year regardless. Make sure you have a decent torque wrench since the shafts need a precise 8Nm of torque so as not to result in premature wear of MTT parts and/or possible frame damage.