The obvious since it's an open ended impeachment as the trial starts the dems can add new false charges whenever they feel like it.
Logical course of action is for the senate to set a deadline for the dems impeachment or they can't accept their open ended impeachment.
The intention is to lord the impeachment over Trump to get him to fall in line with their demands. Do X, or we will get Y Senators to convict and remove tomorrow. This is nothing more than a cudgel to beat him with to get him to do their bidding