Giving Green should be added to that list of EA-aligned charity evaluators—they provide recommendations for high-impact giving in the climate change space (which is probably particularly helpful given how much corporate giving/CSR is focused on climate change)! They also state on their website that they “provide bespoke consulting services to organizations who want to bring more data and evidence to their pro-climate activities”—so they might be able to provide research tailored to different companies needs, or to your new nonprofit!
Thank you for your comment and this reference! I wasn’t aware of this group. I’ve edited the post to include them!!