Hello onyxeyez,
Thank you for your question about image sizes in WooCommerce. This is very likely a theme support issue. The default WordPress themes like TwentyFifteen may offer more support for WooCommerce image adjustments because both the theme and plugin are developed by the same corporation.
However, we are currently looking for areas where our themes can be optimized to provide more default support for WooCommerce, and we thank you for reporting this behavior to us. I will make sure the development team is made aware of it.
In the meantime, if you are looking for a custom coded solution, you may want to investigate the creation of the product post type in your BoldGrid installation to display your products. BoldGrid does not provide this post type by default, but it can be introduced into your installation as a template file without affecting other pages.
Best,
Christopher M.