Buy a DT. No need for a WF on small creek rods since you won't be casting very far. The extended back taper of of some WF lines offer no advantage offer a DT since there is no "back taper" on a DT until you get to the forward taper on the other end of the DT line.
On my small creek rods, I use DT lines by cutting the 90 ft. line in half. Then I add Cortland floating running line
to the cut end of the DT with a loop to loop connection made by whip finishing the fly line core into a loop. When I wear the first line, I swap it out for the other half. It is how we used to make our own WF and shooting heads.
The spare half a fly line stored in a cool dry place on the original spool will last longer than putting the whole line on the reel. There is an extra expense because you need to buy a spool of running line, but I have used the same running line for 25 years. The running line comes in several diameters. For the 4 wt and below, buy the thinnest .027".
You have now basically made your own 45 ft. extended head WF fly line with a spare extended head. That is how the "old fly fishing fogies" tweaked our fly lines.
If your routine casts are not enough to load the rod, you can even go up a line wt to a 3 wt to increase the castibility in tight quarters.