The number is the same. Within reason , we didn't necessarily need the analysis in order to get to the number. But when expressed within the context of the exposure time the *meaning* of that number can be considered different to different users. These appraisals aren't comprised solely of the number, otherwise they would be one page of report and 6 pages of boilerplated assumptions and limiting conditions. These appraisal reports also provide additional information to these uses which are intended to contribute to their decision making if/when they so avail themselves of using it that way.
If you tell a lender the existing use has a very limited remaining economic life or that the site is located in a flood zone or that this home is some sort of atypical construction or floorplan, the number is the same but the meaning of that number to the user's decision might not be. As this relates to the subject's exposure time, if you tell the reader that the DOMs for all sales in the neighborhood are under 3-4 months but for this market segment it's less than 10 days that's information that can contribute to their decision making. And can also contribute to your explanation of why you're being more aggressive with your market conditions adjustments if that's the case.
As with most aspects of appraising, the details (like this) don't become an issue most of the time and under most conditions, but they CAN become an issue under certain conditions. It's not an issue to give a lot of thought to until it becomes an issue. One example is when a market turns down and supply grossly exceeds demand. Yeah, the exposure time was 90 days but the inventory is stacking up quickly and prices are declining as a result, so the marketing time (during which the pricing can be expected to continue to decline) is likely to be longer. The same is arguably true in a market that's entering a trend for pricing increases. It took 3 months to get these sales, but at the current faster rate of absorption it might only take 6 weeks to get a sale going forward.