eWave Deluxe XO on V1.1 PC boards:
10 Ohm and 9.1 Ohm paralleled resistors shown stacked in the R2 position for 20W power dissipation. Any higher than that, they should be mounted off-board on an external heat sink, jumper J3 providing the requisite connections (not installed here). There's little point in beefing up the power handling if the heat can't get out of the box. Worse yet, the XO board is possibly covered with fiberglass or other insulation.
Michael Percy sells 50W aluminum-clad non-inductive power resistors, but a 12" square aluminum heatsink is required for that level of power handling capacity; derate to 20W without one. No 4.7 Ohms, but 4.5 and 5 are available, or parallel 9 and 10. $5.95 each, last time I looked, and a minimum $25 order, I believe I'd want some substantiation that such measures are warranted before implementing these extremes.
a) L1 connects between L1B and R1 hole common with LP1.
b) R1 (4.7 Ohms) mounts in the R2 position, but is skewed and connected to hole L1A.
c) R2 (2.7 Ohms) mounts in the R1 position, also skewed, and connects to the R2 hole common with LP3.
d) J3 not installed.
e) C3 jumpered.
f) All driver and L-pad connections standard, as marked.