Welcome for just east of Toronto, Canada. Congrats on your new Flagstaff. That’s a great floorplan.
In case you weren’t aware Flagstaff and Rockwood are sister brands with the only difference being the interior fabrics and exterior graphics. So as you peruse the forum, threads about Rockwoods will apply to your Flagstaff. The Rockwood 2109S is exactly the same as your 21FBRS.
2019 Rockwood Signature 8290BS, Reese Revolution pinbox and B&W Patriot 18K hitch
2016 Ford F-250 XLT SuperCrew, 6.2L, 4x4, 6'9" bed, 3.73, w/ snow plow & camper pkgs.
2011 Rockwood Signature 8293SS (2015 - 2018)
2010 Rockwood Roo 23SS (2012 - 2014)