Use the woocommerce_bookings_import_batch_size filter to change how many rows the importer processes in each AJAX batch. Larger batches can finish faster, but they also use more memory and may be more likely to time out on constrained hosts. The snippet below sets the batch size to 50 while preserving the incoming value when it already matches that target.
add_filter(
'woocommerce_bookings_import_batch_size',
function ( int $size ): int {
if ( 50 !== $size ) {
return 50;
}
return $size;
}
);