Chaotic Knights should still have a set of role penalties, not necessarily the same caitiff ones as lawful Knights, and maybe not as many, but still something that emphasizes that a chaotic knight is still a knight and is expected to have some pragmatic self-discipline.

Knights who have never consorted with a foocubus have a permanent +1 intrinsic increase damage bonus, which they lose when they do consort with one, with the goal of it being something that is not a huge difference to lose, but does add up over the long run, and which will not stop pacifist knights from using foocubi to achieve the Quest level. This is based on Lancelot and Galahad in Arthurian legend.

Drinking an identified potion of hallucination or eating a corpse or tin of a hallucinogenic monster as a Knight carries an alignment penalty.

Knights get an additional Wisdom-based saving throw against foocubi removing their clothing, flavored as keeping their virtue.

If you talk to King Arthur after receiving the Quest from him, he will tell you to seek the blessing of the Lady of the Lake. (Or just have him tell you this as part of giving you the quest.) After this, your next fountain dip is guaranteed to produce Excalibur, if it does not already exist.

Knights should not receive caitiff penalties against undead.

Give a special message when you fail to tame a dragon as a knight (for whom it’s impossible to tame dragons under any circumstances).

Only knights of XL 7 or higher can dip for Excalibur; but Excalibur is available as a lawful sacrifice gift.

Raise the XL threshold of dipping Excalibur for non-Knight roles to around 9-12. Knights can still dip at level 5.

Knights pass over monsters in their way when doing a knight’s-move jump.

Knights instakill by checkmating all “king” monsters that are a knight’s-move away and are surrounded or cannot move.

Knights start mounted, or else are trained enough to mount their horse from turn 1.

Change the Knight quest artifact to be the Holy Grail. When quaffed from, something good happens; perhaps it needs to have charges or invoking it fills it up so you can drink from it (and you don’t have to drink from it immediately, allowing strategic choices). Should give magic resistance when carried. Possibly gives the effect of a random potion when quaffed: always a “good” potion when blessed, a random one if uncursed, and a “bad” potion if cursed. Or it blesses items dipped into it.