A tiny-nozzle heat gun and solder paste (in syringe)
could be closer to what normal surface-mount assembly
is like. The resistors probably don't care about their
body being heated to solder liquidus temp, unlike ICs
which often spec 10 sec @ 300C max.
A fat flat tip could heat both endcaps at once and let
you "iron, dot, dot" solder the components. You might
even "sacrifice" such a tip (or few) and file out a notch
in the tip such that the "fork" now hits only the endcaps.
Cheap irons often offer only lousy tip geometries. But
back when I was a broke-a$$ student I would pick up
brass bolts at the hardware store (or steal from work)
and grind them to suit - cheapo irons use standard
threads for the tips which are nickel plated copper.
Of course a pack of cheapo replacement tips ought
to be pretty inexpensive too, if you wanted to play
with geometries (less length will let more heat flow
to the tip, you might like a short shaft and a needle
point, or pound one flat and make the "fork" like I
mention, etc.).
But a cheapo iron is also likely not temperature
controlled, only power limited, and will be inferior
for any large thermal mass (including boards with
a heavy ground plane if the solder lands are well
connected to it, thermally).