When doing the player build, a log appears in the Editor log that informs about the progress. The log says something like "[ 60s ] compiled 300 variants" periodically. After the compilation is finished, the total stats are printed. If the "compiled" variants come from the cache, the message above is incorrect, as it's not actually compiling them.
It is also not possible to determine, how much time was spent compiling variants vs fetching from the cache, which makes it difficult to reason about the performance of different parts of the variant fetching pipeline.

The periodic message should be changed to [ 60s ] 300 / 456 ready.
The final message should show duration stats per source in addition to variant counts obtained from each source.