Fmriprep MNI152 3mm missing (and issues running)

I am replicating a paper which is using ABIDE data registered to 3mm isotropic MNI152 template space. Unfortunately, there’s no such option on fmriprep and is missing from templateflow. I tried adding a 3mm isotropic MNI152Lin template file (T1W, brain, mask) to ~/.cache/templateflow/tpl-MNI152Lin3mm and ask fmriprep to register to this template.

The result was a bit weird though, as the final pre-processed BOLD file was 3x3x4 (mm) even though the template file was correct 3x3x3 (mm). Is there anything I am missing?

If that is resolved I would like to add this template resolution to the existing MNI152Lin template. Is that possible to use the existing GitHub repository? I had a look on your contribution documentation but it says updating template is “in progress”. Thank you!