No. Distinguish completion of the adviser’s work from government adjudication, visa availability and the remaining immigration steps.
Use a date only for the event it describes
A prepared application is not an approved case or permission to move. Track actual official instructions and outcomes rather than converting a private service deadline into a guaranteed residence date. Hypothetical example: a survey company principal is told the file will be complete by a stated month and gives notice on a Canadian engagement accordingly.
Completing the preparation and completing the process are different events, and only the first is being promised. Ask the adviser to state, for each date it offers, exactly which act the date refers to and what happens to it if a request for further evidence arrives. Keep a separate list of the dates that come from outside the adviser altogether: the vetting outcome, the official instructions, visa availability and each subsequent step.
Nothing should be given up on the strength of a private schedule, whether a resignation, a lease ended or a school place refused, and no payment shortens adjudication. Record each instruction as it is received, and treat the absence of an instruction as information rather than as a delay to be managed by paying more. Review the household's own commitments against the official dates each time an instruction arrives, rather than once at the start.