You'll want to start with ugly baby, watching for clear windows between the character interactions to handle those important side activities in kaer morhen. The trial sequence opens up several key opportunities disturbance, to bait a forktail, and final trial specifically need precise timing since they become unavailable later. Position yourself to complete these while the main quest chain develops, and remember to check the surrounding areas thoroughly for any missed content.

The isle of mists acts as your major checkpoint here, triggering some pretty significant changes across the world. Once you begin that sequence, a lot of side content especially around velen and novigrad automatically closes off the game gives you a clear warning about this, but knowing exactly when to pause is crucial. The timing window between finishing ugly baby and starting isle of mists is your sweet spot for wrapping up those character specific quests and romance options.

Good to know holding off on progressing uma's storyline at crow's perch doesn't lock you out of anything, so you can use that to pace yourself if needed. Just make absolutely sure you've handled all those side activities before pushing forward with isle of mists, since that particular transition point changes the game state permanently. The recovery window after key story beats gives you enough time to position yourself for whatever content you want to prioritize.