We have prepared the latest bootstraps for both XBY and XFUEL QT wallets:

XBY: https://download.xtrabytes.dev/xtrabytes-bootstrap.zip
XFUEL: https://download.xtrabytes.dev/xfuel-bootstrap.zip

Contents of the zip files should typically be extracted to C:\Users\yourname\AppData\Roaming\Xtrabytes(or Xfuel folder)

This should help with the syncing of the wallets in preparation for the swap.