Rog,
Yes, it’s necessary to have that plywood base for stove support in winter but using an aluminum base for only the stove (to reduce overall 3-season weight) means the three leg support won’t wobble when set on decently level ground. Most sit-on-ground stoves these days use three legs for this reason.
I once made a round 1/8″ plywood base with small aluminum leg “grips” for my MSR Dragonfly stove for winter use until an aftermarket plastic stove/fuel bottle holder hit the market.
Many backpackers are irredeemable tinkerers, thankfully.
Eric B.