SQL Server, SlidingInvisibilityTimeoutand transactions

I’m looking at Hangfire for an email scheduling system and I’m not following what the options for SQL Server do (from https://docs.hangfire.io/en/latest/configuration/using-sql-server.html# ). Are there more details or explanation on what all these do?

Some large sends we do could take an hour or so - so I wouldn’t want the job re-done or to hold a transaction for that long on the database

From what I’ve got so far, Hangfire can use transactions to “hide” jobs till they complete - but that can leave long running open transactions on the DB server. But the Sliding window - https://www.hangfire.io/blog/2017/06/16/hangfire-1.6.14.html - means that instead jobs will update every minute to say they are still going and so we can use that and long running jobs will be ok, and re-start within a (e.g.) 5 mins of restart?