First instinct is yes, leave it alone

BUT only after one simple test

Take the care out for a drive (light or heavy, fast or slow doesn't matter)

Get yourself some nice white copy/printer paper

Wipe the dipstick once then go in for a fresh fluid dip

Place that on the white paper and when it soaks in...

Check the color

Black and burnt smelling - leave alone, top off only when low on fluid

Brown and smells like the engine - it's on the edge, same as above

Reddish-brown and smells ok - maybe start swapping small amounts
(see above recommendations about 2.3 qt pan drain only)

Red lighter than burgundy and smells ok - do whatever you feel like
(but this is the point where if you do change all the fluid, where you will need to keep up on it every 30-40k)

PS, all this fluid discussion, I got a coupon one time from the dealer and the cost of the flush was less than if I got a discount from the parts department to buy the fluid and do myself so I got it for only $125

Good luck