Sign the agreement with the control clauses first, fund the escrow with traced money second, assemble the firm's records and the plan third, then request the consular appointment. Closing follows visa issuance automatically through the escrow.
The agreement first, because everything else depends on what it says
Nothing in the application makes sense until ownership and control are fixed, so the operating agreement is drafted and signed first, with an execution clause tying the transfer of the half-share to visa issuance. The escrow is then funded, which is the moment the funds become at risk, and the buyer's bank records from origin to escrow are gathered at the same time. With the agreement and escrow in hand, the firm's financial records, licences and contracts are assembled and the business plan written around the buyer's actual role.
Only then is the consular appointment requested; wait times vary by post and should be checked before the partner sets any deadline. If the visa is refused, the escrow returns the funds; if issued, it releases them and the buyer takes his half. Do not let the partner's cash-flow needs push the buyer into paying outside the escrow before the visa exists.