Security of logging back into Mozilla Sync using a previously hacked Apple ID?

5 month before, I had my Apple ID/iCloud account hacked. I have since regained control of the account and updated all my security settings (enabled 2FA, updated passwords, and removed unrecognized devices from iCloud). And I used my previous hacked Apple ID as a iCloud Mail now, (only recieve/archive mail) and change a new Apple ID,My questions are regarding my iOS device and the Firefox browser :-Is it safe to log back into Mozilla/Firefox Sync using this same previous hacked Apple ID?Is it secure to recover my device from iCloud backups and sign back into the same Apple ID at the iOS level? I want to ensure no malicious syncing or lingering exploits will compromise my Firefox data,device data,App data,iCloud data other remaining data services on iOS .Thank you.