Those nemodium oxide magnets in the large MagFloats are unreal, even through 9/16" of glass it will hold a 1500, i'd have to guess it would stand up to the torque a 2600 at that angle as well.

The only other option we've used with the Seios was to bury the powerhead in rock work. One of these days I'll get around to making some 'special' agrocrete rocks for them, similar to the Tunze system type, minus the pricetag.