Inline base64 shouldn't have any head of line blocking or slow rendering issues, unlike embedded images-as-mime-attachments, which will normally result in one HTTP request to gmails servers per image, and without QUIC you'll get head of line blocking and limited/no HTTP pipelining making that very slow.
Inline base64 should perform fine for small images up to ~10k images I'd guess on most hardware.
If your email contains more than 10k math equations, perhaps email isn't the right tool...
Inline base64 should perform fine for small images up to ~10k images I'd guess on most hardware.
If your email contains more than 10k math equations, perhaps email isn't the right tool...