I've been involved in a few deals of that size (acquiree and acquirer) and to my knowledge, no acquirer ever had an IB. If funded, acquiree could lean on angel or VC who's seen a lot of deals.
As policy, I don't think anything like immigration status should be a consideration when deciding on charges. There's a reason our ideal of justice is depicted as blind. Perhaps it could be considered as mitigating/aggravating circumstance at sentencing.
One tax advantage to approximating an index with individual stock positions is "tax loss harvesting": sell one stock at a loss and buy an equivalent. e.g., sell Coke and buy Pepsi. An advisor told me that you can add ~1% to your after tax returns. You need sufficiently large positions such that rebalancing transaction fees are negligible.
That might obviate a service like this, or else enterprises will want a service like the to broker auth and monitor access to their SaaS as well.
There are CASB (cloud access security broker) products now that do the monitoring and reporting aspect, though AFAIK don't participate in auth.