Here is just my not-so-pressing suggestion. Wouldn't it be cool if there was a page to track the website's operational status?
Like how long the planned maintenance has been on going or even the ETA and then also a maintenance log/ changes of log of sorts. I am not a programmer, so I am not sure what I am suggesting requires JavaScript or not

No, it's not necessary. When the site goes for maintenance, then the homepage automatically will redirect to the maintenance page, where you can notice about the maintenance. It's true; additionally, they could add estimated times for the maintenance, but since it's related to coding, developers could estimate the time. But it's quite hard to predict the exact maintenance time. If an error comes during the development, then it would take more time.
However, the developer could at least adds the possible timeframe to understand the site would come online within that period, but it's really not mandatory.
Both options are feasible and could be implemented;
but I believe that temporarily disabling deposit, if maintenance is ongoing is a better option.
Just to disable deposit with a warning note that "maintenance is ongoing, deposits is temporarily suspended, try again in few hours later or few days later as the case may be."
This will prevent more inflow of funds that could disrupt maintenance.