I am an extremely tiny angel investor, which means I periodically send small checks to startups in return for an equity investment. This has historically been very toilsome for all parties.
Theoretically speaking, every conversation is independent of each other.
A startup I had promised a check to said "OK, we're doing our friends-and-family checks via an AngelList Special Purpose Vehicle."
It's, effectively, an extremely specialized one-use one-time computer program which pretends to be a company.
Angels invest in that company.
That company invests in the target company.
A startup I invested in back in 2012 exited. Yay! And I got several hundred pages of documents to review as a result of it. Absence of yay.
The ideal UX here is "I trust you. There's a number. Pay me; I tell accountant"