epi2anat & mask issues despite blip correction

Hi, my EPI-to-anat registration QC output shows the ulay as more distorted than I would expect, given that I'm applying -blip correction in afni_proc. Multiband (7), single-echo EPI data were acquired with AP phase encoding; I have AP and PA fieldmaps that I'm using as forward_dset and reverse_dset respectively.

epi2anat QC images usually look ~like the below, across subjects in my dataset.

Are these results more or less the expected outcome (I know SDC can't fix everything), or is there a way to improve registration and mask accuracy? (or am I doing something incorrectly in the afni_proc pipeline....)

sub #1






sub #2






AFNI version info (24.1.22):

  afni_proc.py \
                        -subj_id "${subject}_${session}_${task}" \
                        -dsets ${epi_run1} ${epi_run2} \
                        -copy_anat ${anat_cp} \
                        -scr_overwrite \
                        -anat_has_skull no \
                        -anat_follower anat_w_skull anat ${anat_skull} \
                        -blocks despike tshift align tlrc volreg mask blur scale regress \
                        -radial_correlate_blocks tcat volreg \
                        -blip_forward_dset ${fmap_ap} \
                        -blip_reverse_dset ${fmap_pa} \
                        -blip_opts_qw -plusminus -noXdis -minpatch 9 \
                        -tcat_remove_first_trs 0 \
                        -align_unifize_epi local \
                        -align_opts_aea \
                        -cost nmi \
                        -check_flip \
                        -tlrc_base MNI152_2009_template_SSW.nii.gz \
                        -tlrc_NL_warp \
                        -tlrc_NL_warped_dsets "${dsets_NL_warp[@]}" \
                        -volreg_align_to MIN_OUTLIER \
                        -volreg_align_e2a \
                        -volreg_tlrc_warp \
                        -volreg_warp_dxyz ${dxyz} \
                        -volreg_compute_tsnr yes \
                        -mask_import Tvent ${template_imp} \
                        -mask_segment_anat yes \
                        -mask_segment_erode yes \
                        -mask_intersect Svent Tvent CSFe \
                        -mask_epi_anat yes \
                        -blur_size ${blur_size} \
                        -blur_in_automask \
                        -regress_motion_per_run \
                        -regress_ROI_PC Svent 3 \
                        -regress_ROI_PC_per_run Svent \
                        -regress_make_corr_vols WMe Svent \
                        -regress_anaticor_fast \
                        -regress_censor_motion ${censor_mot} \
                        -regress_censor_outliers ${censor_out} \
                        -regress_apply_mot_types demean deriv \
                        -regress_est_blur_epits \
                        -regress_est_blur_errts \
                        -out_dir "${procDir}/${subject}/${session}/proc_sst" \
                        -html_review_style pythonic