It's a must trust, can't verify situation. You're trusting them to have deleted the setup keys (it's impossible to prove you've deleted something). If they haven't, they can unilaterally withdraw your funds too!

Leia isso: "Spark’s trust model is minimal and transient: 1-of-n operators must act honestly at the moment of transfer, and even if all fail, your pre-signed exit transaction lets you reclaim your Bitcoin on L1 unilaterally. No permission from Spark or anyone else." Fonte: https://x.com/davidmarcus/status/2030295720461525467