Then every few months I send to Strike to consolidate UTXOs before sending to my hardware wallets.
I don't think you actually have UTXOs in robinhood, isn't it paper bitcoin? But I guess what you're saying is still valid, send to Strike in one chunk then withdraw to cold storage.
Just a single UTXO when I would withdraw from Robinhood. However, instead of adding a dozen little UTXOs from different platforms, I would put them all on Strike and then add 1 UTXO to my hardware setup (from withdrawing all from one transaction from Strike).