Improve topaz picking

Dear all,
I have a quite challenging set of mics. After denoising and very generous blob picking, I got a few 2D classes for a following topaz train. From 20k particles in these 2D classes, I got 55k good particles after topaz train/extract, which is still low, but there is an increase.
However, when I check which particles have been picked, I notice that there are a lot on unpicked particles (I assume from orientations which are not present in the 2D classes used for training). What ways are there to improve the picking / get topaz to pick more.