I think the only shot of getting documents is if we get witnesses.
The House held off playing rope a dope through the court system knowing any final resolution might not come into late 2021. The system can be "gamed" through the courts.
Whereas, in the Senate Trial, with a Chief Justice presiding, any claims of Executive Privilege can be resolved quickly. Remember, EP can NOT used to cover a crime.
In regards to witnesses, I'd gladly allow for the Bidens, Hillary, Obama or anyone else the Senate Repubs want to hear from in exchange for Bolton, Mulveney, Pompeo, Giuliani, Pense and TRUMP.
The American people deserve the truth!