Using @Someone to discuss with colleagues is ok, but this communication is spread out any where, we can’t find them when we need them.
My suggestion would be an integrated live chat feature, which can be called anywhere in the HubSpot. The conversations can be associated with certain CRM objects, but they are also put together in one place so that we can easily retrieve them. The layout can be similiar to any of the AI Chat tools on market - there are topics (which can be associated to records), and they can be searched and called out anytime.