Yes that’s the only way… which is what I’ve been doing when pressed. However, inevitably the detection is wrong anyway (especially for 96k projects), so you end up having to make so many manual adjustments that it’s easier to build the tempo map from scratch. For projects that include time signature changes (for some reason I get too many of those!), there’s the added hassle of having to delete a whole bunch of tempo points too. Bottom line is that the tool is broken.
Not sure if it’s related, but another issue that got me last week was hit point detection in a midi track. The midi was recorded in to a 96k project without click. I needed to build a tempo map from the midi event and tried the detect process. It got it badly wrong per bug, but then I dropped the project back to 44.1 (and in trying to find a solution also exported the midi and imported into a fresh 44.1 project), however the hit point markers in the midi file persisted making it impossible to quantise or do any tempo detection. Ended up getting the musician to re-record into a 44.1 project.
Overall this whole area of tempo / tempo track / hitpoints seems to be going down hill in Cubase.