we've talked about moving our insurance up to the 'hold co' level, but haven't done it so I'm curious as to how this goes. I'm the operator and owner though so this may not apply. Note, you may not get benefit of savings though if the companies have different requirements (an MSP will have a higher cyber policy, a tree cutting company -> higher workers comp, so on)

If it's just an empty shell LLC right now most insurers won't actually give you a professional liability which is what would theoretically you would need. For SBA lending purposes; though, and I'm sure this isn't a super popular opinion, but what I've seen is that they usually just require a commercial general liability policy to check the box. A basic CGL you can get anywhere, as it won't actually cover anything. I.e. it'll just cover somebody slipping and falling in your office but not anything related to actual searching or operating. This should run you like $1,000 and will usually satisfy the lender. The op-co should drive the real insurance requirements. From a risk perspective, once you get your policies in place you can then add the holdco (or vice versa with the opco) as an additional insured.