Node Streams - Piping readstream, compression, cipher, writeStream - Buffer size problems

Question

I am trying to use a stream pipeline in Node, but running in a problem where i cant get the number of chunks in a stream accurately when i include a gzip transform.

  const readStream = fs.createReadStream(group.selectFile,{highWaterMark: group.BackpressureBufferSize})
  const writeStream = fs.createWriteStream(path.join(path.dirname(group.selectFile), 'encrypted_' + path.basename(group.selectFile)), { highWaterMark: 64 * 1024 });
  const gzip = zlib.createGzip();
 const progress = passThroughStream() 

// Used only becuase i cant get a 'data' event on writeStream, so i create a 
passThroughStream which doesn't manipulate the stream, but rather captures data on chunks  and data length.

  totalChunks = Math.ceil(totalSize / group.BackpressureBufferSize)
    let currentChunk = 0;
    bar.start(totalSize, 0)
    progress.on('data', (chunk) => {
      totalBytes += chunk.length;
      currentChunk++
      bar.update(totalBytes, { currentChunk, totalChunks });
    })

 const streams = [readStream, gzipstream, cipher, progress, writeStream]
  
    await pipelineAsync(...streams)

Everything works fine if i dont include the compression stream, and the number of chunks is known by diving the totalsize of the file by the backpressure amount, However when i include gzip transorm the chunk varies between 16k and 8k, i thought i could set it like i did with the readstream and writestream so that each pipe has the same buffer size.

My question is:

1. Can i control the highwatermark buffer size for gzip it seems defaulted to 16k and 8k
2. If i am piping a readstram with a much higher water mark size of 64k, does the next stream like the gzip transform slow down due to backpressure because it only accepts 16k at a time?
3. is there anyway to get the total number of chunks with the compression?