I made a 'hood / shroud' using 1/4 ply - 45' 'wings' to each side that went to the full width of the saw table itself, 45' top pc that cleared the blade guard in the 'fully back' position. the bottom extended forward to the back of the fence pc so nothing 'fell thru'
drilled a hole for a shop vac in the top at the 90' cut position. it caught (near) all the sawdust - but sometimes the sawdust will accumulate in the corners - especially at angle cuts. not a big deal, plunk the rectangular suck'em'up fitting on the end of the vac hose and clean it out as needed.
I have the RAS mounted to the right of a 60" workbench - lots of fiddling&futzing needed to get the saw table at the right ht plus level to the saw arm travel, but oh well....
the theory was to use a 10' length of aluminum angle - slotted for 1/4-20 threaded inserts in the maple top - as an 'extended' fence. makes for nice when cross cutting - long long fence. but I wanted to use it for creating the first 'true edge' on rough cut. putting the (if any, HAH!) concave edge on the super-long fence, ripping any 'excess width' off the convex edge to produce the first straight edge.
neat idea, but good implementation requires a long long fence on both the infeed side and the outfeed side. outfeed side in my setup is "nuttin' but air" - sigh.
so, depending on what all you do - you may need a long fence on both sides - but for general purpose RAS - a long fence on one side is a real boon.
oh, if you drill your bench for thread inserts, get some (1/4-20) set screws to put in the inserts when they are 'idle' - keeps the saw dust / dirt out and saves 30-40 minutes of painstaking vacuum sucking while needle dirt dislodging . . . .