Try closing the gap first.

Does the rev counter do anything strange during the problem ?

If you had a cheap USB oscilloscope, you could hook up to both crank/cam sensors and record them for viewing to see if they are dropping out at all.

If you can control when this problem occurs that would make life easier as there could be a lot of viewing there.

A very violent dropout could suggest a main trigger problem though ( whether that's sensor, wiring etc would be up to you to trace ) But again the fact it is boost related....trigger issue seems unlikely.

And are you sure MAP sensor etc is healthy ? If this was doing something strange it could cause problems. Again fairly easy to test/record with a voltmeter when driving or with a Mityvac or similar pressure source.