Not on the instalments alone. The qualifying capital must be invested or irrevocably committed to the enterprise, so money still owed under a buyout agreement does not count until it is received and placed at risk.
A right to be paid is not capital at risk
The distinction is unforgiving and it catches sellers of family businesses regularly. Grigor holds an enforceable contract, which is valuable, but the enterprise does not have his money and he has not lost the ability to get it back. Neither condition of the requirement is met.
Three responses exist. He can wait until enough tranches have been paid to fund the full qualifying amount and file then. He can renegotiate the buyout for a larger upfront payment, which changes the commercial deal and should be priced accordingly.
Or he can fund from another lawful source now and treat the buyout proceeds as repayment to himself later, which is clean only if that other source is itself documented to the same standard. Any adviser who suggests filing against a schedule is describing a case that will fail on its first substantive question.