If the price difference is significant then sure. My experience booking 3-5 days ahead of time is there isn't much difference. In addition to no credits to keep track of, which don't seem to be your concern,

- simplifies expense filing

- if paying with a personal card (vs a corporate card), i'm not floating extra cash that is now converted to a credit

- full fare is less likely to get bumped on overbooking

- more miles / credits towards status