Yes, it is generally safe to update to SP Page Builder version 5.6.0. The issue reported in the forum is minor and should not affect most installations.
Before updating, please ensure your Joomla database has no issues. You can check this by going to System > Maintenance > Database prnt.sc/MWsmW-v8rkUY. If any problems are listed, select them and click the "Update Structure" button to fix them prnt.sc/3XEtDtokytaJ.
As always, it's strongly recommended to take a full backup of your site before performing any updates, to ensure you can restore your site if needed.