[DesertRatTom]

Stick has suggested using a snorkle attached to the bottom of the router to improve upward air circulation through the router, to cool the motor. But his would also improve the up-flow through the insert and possibly improve above the table DC.

And, that is a really handsome router table!

 

[DesertRatTom]

My router fence has a safety shield that I don't always use, but it partially encloses the bit which will restore some of the air flow to the DC port behind the fence. The one shown is a Jessem and requires a fence with a T-track. Theoretically you could add an extension (Lexan) so you could keep the fence further away, or even a DC port through the shield, directly above the bit. As an alternative, you could make a shop built unit. It would not help with DCwhen cutting a stopped or full dado.

Here are a couple of sources

This one is tinted orange but is only $7: https://www.amazon.com/Router-Bit-G...s=Router+bit+guard&qid=1556582209&s=hi&sr=1-7

A little smaller kind of yellow tint, about $6: https://www.amazon.com/Router-Bit-G...rd_r=ZCSQ2BZ2410SCM734Y17&qid=1556582317&s=hi

JessEm's clear bit guard in the pix is available direct from the company, about $10: https://jessem.com/products/bit-guard-for-mast-r-fence-ii-rout-r-fence-mast-r-fence