Doubt if it's the contact that's a temperature issue. Are you sure it's not ashes built up and compacted in the rear corner behind the ash pan? The sloped rear of the ash pan works very well to pack the ash into that space over time.
When we burn 24/7, whether with the current Oslo or with the prior Encore, we do/did not rake the ashes all around so they fell down by force. Keeping a layer of ashes in the stove is better for secondary combustion in the Oslo, as it keeps the firebox hotter, though that should make less difference in a cat stove. Still, it was not our practice to rake the ashes through the grate every day. We used to rake the ashes around just enough to redistribute them into an even layer, letting the ashes fall naturally through the grate over time. A week of round the clock burning, loading the stove 3X per day, resulted in a full, but not quite overflowing, ash pan, and this stayed constant over months of nonstop burning.
With the Oslo, the ash pan fills up in 4-7 days depending on how much wood is burned. The Oslo has a larger firebox than the Encore, so we burn more wood (and get more heat) per hour when we're really cranking than we did with the Encore. Hence more ash production.
Wood type also plays a role in ash production. For a few years I burned a lot of barkless oak, and found that the amount of ash was much reduced, only getting maybe 2/3 of an ash pan full per week, so i think the bark must have more residual uncombustable solids than the interior wood.