Second, why do you dismiss battery operated scopes? A proper one is as safe as a proper DMM, and if you showed up as an electrician to work in a panel with anything else you'd be thrown out.
No it's not.
Hint: look at the connectors:
Yes it is.
Hint: look at the connectors!
Discussing a "proper" battery powered scope (Scopemeter) ... Like a Fluke, not DSO-xxx hobby class rubbish.
My Fluke has the inputs (including the BNC's) insulated so that you cannot contact metal, even on an unconnected BNC socket. The probes are fully insulated, no metal of the BNC is exposed.
Bare input on the scope is rated max. 300v (4kv surge). With the standard 10x probe, it's rated 600v (6kv surge).
HV probes are available which are rated for many kv - Highest input range in scope mode, configured with a 1000x HV probe is 100kv!
And, yes .. I agree, if you showed up to my building planning to look at my 3 phase mains, or VFD outputs with a typical bench scope, I'd send you packing.
Dave