These endgames are highly complicated when there are seven to fourteen tiles left in the bag for timing concerns! Let's dig deeper into the real edge of the pre-endgames!
You are player 2. Score: 426 - 567
Pool: ?EELLOOORSSSTTW
Opponent's last play: N4 OOT (18 points)
Your options: Exchange, 3H VIV(E) (11 points, keeping BGUU), A14 BI (25 points, keeping GUUVV), 4A (F)UGU (16 points, keeping BIVV), M7 BI(JO)U (17 points, keeping GUVV)
Opponent's options: 8-letter bingos through the floating E and R through K column; Bingos on row 15 starting with the D at 15B
Potential plays on next turn: 8-letter bingos possibilities: through the R and E of REQUINS, I and N of INFULaE, 8-letter bingos starting with D of GRANITOID on row 15, nine-timers through the D in the same spot; plays overlapping QI; plays hooking CHLAMYDIA(E/L), two-letter parallel plays blocking the D of GRANITOID
Subgoal: Maximizing the winning conditions while also staying ahead of the worst-case scenarios through the D of GRANITOID
Resolution: You best off exchanging six tiles keeping just an I. You have the last I on your rack for multiple potential options, including QI overlaps on L column, maximizing bingo possibilities (including the potential triple-triples through the D of GRANITOID). Holding onto the I allows you to hit many extra bingo possibilities to outrun a vast majority of player 1's plays, including all of the four triple-triple possibilities through the D (EDITRESS, IDLESSES, ODOMETER, and ODORLESS). Here are some eight-letter bingo possibilities with and without keeping the last I:
Through the R of REQUINS: 412 with the last I, 375 without the last I
Through the E of REQUINS: 496 with the last I, 399 without the last I
Starting with the I of INFULaE: 19 with the last I, 12 without the last I
Starting with the N of INFULaE: 38 with the last I, 22 without the last I
Starting with the D of GRANITOID: 123 with the last I, 59 without the last I. Keeping the last I allows you to hit way more bingos starting with the D, thanks to the possibilities of DIS- words.
Triple-triples through the D of GRANITOID at the second position:
4 without the last I (as mentioned above)
9 with the last I, including the additional IDEALESS, IDOLATER/IDOLATOR, IDLENESS, IDOLISER/IDOLISES, and ODORIZES plus the aforementioned EDITRESS and IDLESSES
Keeping the last I results in 1,097 bingo possibilities, versus only 871 without the last I, which is 226 more. That's a substantial increase.
It is worth noting that there is a sneaky extension of (PHENETIC)ISTS on the O column.