The output displayed in System > Firmware > Updates (both firmware upgrade output and audit results) is not streamed line-by-line. Instead, output appears to be buffered and flushed in large chunks, causing long pauses followed by sudden bursts of text. Live streaming would give better visibility into progress.
Yes, noticed while testing:
https://github.com/opnsense/core/commit/5de581cd4416
But the change was already in 26.1.8 so we'll fix for 26.1.10 which means in 26.1.11 the updates log will be back to where it was. ;)
Cheers,
Franco