There is no 145 for 23/24p projects. This is because the data rate (per second) is lower when the frame rate is lower, when using the same compression.
So DNxHD115 (23/25) equals DNxHD120 (25) and DNxHD145 (29), and DNxHD175 (23/24) equals DNxHD185 (25) and DNxHD220 (29).
You can transcode to 29.97, as you did, and then you’ll have sources that are 23.976 with a pulldown added. If you cut those, you are likely to break pulldown phase. Not problematic in some cases, but not the cleanest workflow.
Guess you got stuck on the number 145, which is understandable, but is just named differently in a 23.976 project.