If a lot of people are using that phrase on you, maybe it’s not an “excuse” people use against you and perhaps you should evaluate how you interact with other people, especially while seeking help…
Once again, we’re happy to provide help to you and answer questions - all I’m asking you to do is consider having a more professional approach when an answer to one of your questions frustrates you.
As for the 24V power supply, if you just plan on running your alarms straight off of that, it wouldn’t necessary need to be filtered DC. Most alarms that are ran off of FWR can also be ran off of “regular” DC power that something like 9V batteries or a 120 VAC to 24 VDC transformer would provide.