• The "address limit" tells btcrecover how many 'address_indexes' to derive (address_index starts at '0'),
  so if you're not certain of your address' index, better leave it with higher or default value.
  But if you're absolutely certain that it's the very first address that you've derived (not just the first to receive bitcoins), then '1' is enough.
  
  Is there a way to find out whether it's the first derived address or not? I do have the wallet in my Ledger desktop app. I also have the xpub but wasn't 100% certain I got it the correct way so thought using the address would be better.
  
• You'll be providing it with your address with --addrs so why do you have to provide the format?
  Anyways, --skip-uncompressed can be added to skip searching from uncompressed pubKeys which Ledger doesn't support.

I think I read somewhere that it searches all the formats and stating the current format will reduce the search parameters. Perhaps that's been updated in the latest version?