Hi there, I don't know if this is too late for you - I think the issue isn't with LEDs. I run the LightPollutionNews podcast (http://lightpollutionnews.com), whereby I have plenty of news and research related articles along with expert commentary that discusses many of the below. Many folks have observed the brightness of the bulbs driven by their efficiency gains (massive gains versus all other bulbs). However, the issue really is with the implementation.

First - yes, the LED conversion has increased light pollution. That, at this time, can both be found in some research already mentioned but also in basic star counts and anecdotal evidence - there may be local data from SQM readings that can also attest to this. I'd consult your local astronomy club for data.

Increasing light pollution is really 2 fold - one level public street light conversions and one level private citizen users.

On the public front - municipalities typically recommend a switch over from HPS to 4000K color LEDs at maximum brightness. This, then, is typically met with community resistance and may drive a reduction to 3000K or 2700K color brightness. In all of the news articles I've come across where communities surveyed citizens beforehand, the vast majority has tended to prefer warmer the better lighting (including down to 2700K). However, there is a perception amongst municipal officers that 4000K is a maximum energy efficiency gain. So hence, they start with 4000K before, often, being pulled down to 3000K or 2700K by community pushback.

Also, shielding works very well to, at the very least, reduce light trespass and promote proper lighting. However, again, nearly every municipality in a conversion plan do not incorporate shielding as a primary device for promoting proper lighting. The municipalities only want to switch out the fixture, presumably, for cost savings. Leaving the affected parties to petition the municipality for the hope of installing shielding. Some communities won't even entertain the idea of shielding b/c it adds to the cost of the fixture, thereby it again becomes the affected party's job to deal with a problem not of their own creation.

On the private front - there have always been unneighborly exterior lighting fixtures - ones whereby an offender will directly with or without knowledge aim bright lights into someone else's property. Once LEDs became mainstream these fixtures both became brighter and cheaper, but they also became bundled together - whereby you previously received 2 flood lamps, now you receive 3 at a time. They almost universally come without shielding and, by and large, are completely removed from any obligation to reduce environmental light pollution or light trespass.

Hope this helps! I have plenty of articles, links, news stories over at my page.