Dave,
I occasionally "bail" when toe-holds are thrown at me (especially when they are standing) and roll out, going with the hold.
From no-gi Machado style quarter guard, if I lose control of wrist control on a good guy, they'll attack the foot near the hip. This is also one of my favorite ways to clear a "good" (I hate knee up half guard players) half guard and get them flat on their back. When I attack the foot, and they "boot" I can change the half guard to my advantage. However, I suffer the same fate from any quick and determined toe hold/heel hook attempt in my half, as I boot to escape, and end up playing a temporary lock down game until I get back to knee in front.
Any first look negatives to my general toe hold attacks and defenses from the half and open guard?