Getting totally eaten up by fees, with the small amounts I'm sending, but the Alby is custodial, so I can't collect a larger amount there and then send it, all at once. Moving things peu à peu to Phoenix, and from there over Boltz to my hardwallet.

This is all crazy-difficult. 😭  

 The trade of to fees is going the KYC route. 
You can send to lightning on strike for no fee and then withdraw to on-chain for free as well.

But you know what they say about when things are free... 

 You should probably send a million sats for UTXO management.  

 I don't have a million sats, unfortunately.