It seems like 1A is about the best available. Does anyone make anything that can do more than this?
Some regular single mode drivers can be modded by means of a resistor change. I haven’t tried one with a boost driver but tried it with a buck converter, to lower the output in one and to raise in one. Was easy. I don’t believe you’ll get more than 1.8A or so, though. Some elements may need to be changed and a better heat disposal might be needed.
Deerelight claim 1.2A on the Javelin pill
I've taken tailcap readings of 1.9A on 2AA (tested with eneloops which read O/C voltage of 1.36V ea)
On 3AA (with the Javelin extension tube) I get 1.5A at tailcap.
This is on the XP-E pill but I think the 0.9V-4.2V driver is the same for all of them.
Only problem is Dereelight don't list the driver separately. I guess you could always send Alan an email - he usually replies promptly.
http://www.videofoundry.co.nz/ianman/laboratory/research/driverlist.php
You can sort by drivers and their outputs there.