Posting to this thread after long time dormant...
The problem I encountered was poor behavior owing to absence of the ~25mm long, 4mm dia thin metal tube (a thermal link or shim).
While looking for "how to improve my 936 soldering iron" a few days ago, I found this thread, and in particular, the link to the Russian-language youtube video showing use of pencil graphite as a thermal link.
I didn't use that procedure, but it started me in towards a solution I've found is working well for me.
I picked up a roll of thin copper sheet with idea to use it as thermal link material (filling gap between outside wall of the ceramic heating element and inside wall of the tip). The material I tried is K&S Precision "Copper Crafting Foil: 0.003" Thick x 12" Wide x 30" Long (1 Roll)". About USD 15 at the local hobby store. The material is very soft copper foil (so it can be wrapped around the thermal element and keep it's shape.)
After a few experiments, I found that a 25 x 25mm piece, rolled over the end of the ceramic heating element (so end of the element is flush with end of the copper foil) created a reasonable thermal connection between the two, greatly improving performance.
Testing with a thin "needle" style tip (Chinese clone of Hakko 900M-T-I) on a no-name Chinese clone of a clone of a 936-style solder station, using 63/37 wire solder 0.8mm (1/32") dia.
Without the shim (just the white ceramic element heating the tip), the solder station needed to be set well over 800F to create enough heat in the tip to be usable for any soldering. Downside of this setting is that the idling tip temperature would get high enough to melt/deform the end of a clone 900M-T-I tip.
With the shim (and the above station, tip and solder), a setting of 600F is adequate for small (SMD pad) type soldering; 700F is adequate for pooling small blob of solder on a ground plane (not instant, but quick enough, and the 900M-T-I tip isn't appropriate for that use case anyway.)
The shim seem to hold it's shape sufficiently to allow re-use (changing tips), however, I need to take a little care when placing the tip onto the heating element+shim, as there is much less gap than there was before.
Hope this is helpful.