I disagree with the statement that LED retrofit lamps wouldn't be bright enough...that's what's in my garage door opener. They're available in up to 100W equivalent versions. I actually think it's a great place to use them as the short burn time won't cause heat issues, and the LEDs are immune to vibration and frequent switching. If you install a decent quality LED retrofit lamp you may never have to replace it again. The only way it might be a problem is interference with the opener's electronics.
For LED alone it would be indeed the best place for higher output. But the problem is with their ballast electronic: Each time it is switched ON, the capacitors get current surge. Normally that is of no issue, but when something flashes the lamp 100x per day and still it makes for just few minutes burning time in total, the turn ON stress could well become the dominant degradation mode and the primary cause of failures.