I added the secondary one to avoid that someone else claims it (because it’s freed up after linking your domain), and then creates trouble (I unfortunately have some bad experience with that on Instagram, with no way to discuss/correct 🤡)

photo of secondary account profile text stating "A secondary account to redirect to my main account @leonmoonen.com (proving once more that any problem in computer science can be solved with another level of indirection ;-)"

I’ve "solved" this by following their suggestion and claiming @leonmoonen.bsky.social as a secondary account that points at the primary one @leonmoonen.com, but it’s not very elegant…