A pro rata right lets an investor participate in a future round to maintain ownership. It does not settle whether you should.
Selection can work against the offer. A round without an outside lead may leave the full allocation available. A round where new investors are competing for room may cut it back. Easy availability should increase the scrutiny because it may reflect financing risk rather than opportunity.
Then there is the memo you already wrote. After two years of board calls and answered texts on Sunday, it is easy to judge the follow-on against your entry price and your involvement. A blended cost basis is arithmetic about the past. The next dollar earns its return from the current price and future value.
So I would write the follow-on memo before reopening the original, with two lines near the top: what this check buys, and what evidence would let a new investor pay more in the next round. If the honest answer is that the existing syndicate will need to bridge it again, price that financing risk into today’s check.
Reserve policy belongs at the first check and gets revisited on the fund’s own schedule. A live round replaces that schedule with a closing deadline.
If the underwriting says no, record whether the problem is price or something price cannot fix. If it is price, name the number that would change it. That keeps prior ownership and effort from becoming reasons to invest more.