Recently, a glitch was found in Farewell that allows the player to keep two dashes from Start until the end of Determination. Here's a video showing both parts of the skip, as performed by Zkad:
With the discovery of this skip, some changes have been made to the Celeste SRC leaderboards. IL speedruns of Farewell (both Clear and Moon Berry categories) are now split into two sub-categories: Unrestricted and No DTS.
The reasoning for making this split is that this skip fundamentally changes how much of the level is played, so we wanted to provide leaderboards for each way you can play the level. That being said, we will revisit this change in 3-6 months to see if one or both of these two splits can be undone due to inactivity of any of the four sub-categories.
Fullgame categories that play farewell allow the use of the glitch and their leaderboards were not split. Some reasoning contributing to that decision is that the skip affects a much smaller portion of the run. Because the scope of the skip is narrower in the context of a fullgame speedrun, it's more comparable to a routing choice that a player makes when learning the category, instead of running a largely different category—much like the options in Temple and Reflection for Any%.
One final note: the Unrestricted sub-categories are currently only for runs that successfully perform the second part of the skip, meaning any runs completed with the infinite height glitch which fail to preserve 2 dashes will be put on the No DTS board. This is an edgecase reserved mostly for IL PB's in fullgame runs that fail the skip and elect to continue, so it's open to change, but this was chosen because it seemed silly to punish the use of a glitch that amounts to timeloss.