For the most part I agree with Bobj3 regarding the RT, however there are materials like fir and SYP that do produce long cutoffs strings or in the case of fir long brittle break offs that will clog your 2 1/2" intake and hose.
As for 4" intake and hose from the RT to the collector they're pretty safe from clogs by both materials, however in the case of my Delta, where the debris enters "Y" connector below the fan housing there's a split rail reenforcing bridge that collects debris from the planer, jointer and TS and block free movment. The base of the fan housing also has a cross bridge that packs up with material. I pull the "Y" off clear it and the housing bridge when ever I use the planer or jointer.
If you have gates set up, the closer to the collection system the better you can close and or open any combo. I can only think of med to large production shops that would have a need for more than 1 or 2 lines open at once.
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