PNG vs JPG for converted HEIC photos
Both formats start from the same decoded image; the difference is how they store it. PNG uses lossless DEFLATE compression, so re-opening the file gives you bit-identical pixels and it supports a full 8-bit alpha channel. JPEG uses lossy DCT compression, discarding detail your eye may not notice but a machine certainly will. If your workflow involves masks, layers, or matching a brand colour exactly, PNG is the only correct answer.