In the episode The Nth Degree, Barclay is modified by the Cytherians in order to make contact. Barclay goes super genius and starts to make radical changes to the Enterprise in order to destroy the probe as well as travel to the Cytherian's home.
So the shield strength is increased 300% in order to survive the proximity of the full spread torpedo explosions. Do we know if this is a permanent change? Does Starfleet know of this, and apply the technology to all starships? Or do we know?
Does the holodeck have that interface he built stored, or any data on how travel beyond maximum warp is achieved? Or are humans too feeble to understand whatever data is left after this incident?
So much as I recall there's no mention of Barclay's improvements past this episode, but I'm also not professing to be a walking index of Star Trek knowledge... maybe there are some here who can answer this?