Duh.. it did not even occur to me to block the air intake. The fasttech bases that I got can be turned to a position that totally cuts off the air; I'll try that next time I refill!Why some topfills have a juice flow control you can shut off while filling. But they still tend to flood a bit.
Here again are the links for the fasttech subtank bases and top-fill tanks:
$4.53 Replacement Air Flow Control Valve Base for SUBTANK Mini Clearomizer - stainless steel at FastTech - Worldwide Free Shipping
$6.68 Replacement Tank Set for SUBTANK Mini Clearomizer - stainless steel + glass at FastTech - Worldwide Free Shipping
Another possible negative for some folks: it requires a large amount of grip and torque to turn the air adjustment ring on the base, at least on the ones that I got.