Yes, here is a dirty script in Deno that takes your ActivityPub ID and fetches all the people you follow and converts them into a list of Nostr pubkeys: https://gitlab.com/alexgleason/nostr-fedi-followers/-/blob/main/script.ts?ref_type=heads

I had written this like 6 months ago and started building a UI for it on mostr.pub, but it was really hard to make it work right because I had to essentially implement a full Nostr client into the Mostr homepage. I will return to this after fixing some other issues with the bridge.