Robin mentioned the idea of dropping the Defenses of all the foes by 1 point to remove the 'whiff factor' and increase the PCs chance to hit their foes to increase speed of combat. I'm strongly leaning towards this for a variety of issues.
We have monthly sessions of limited length due to babysitter issues, so the 45-60 minutes per sequence it's taking the five players right now is too long. Experience with play and more tricks on my end will speed that up, but probably not enough. On top of that the players wanting longer bridging scenes and the large number of whiff moments...er...emotional down beats due to losing a combat resource caused by poor dice rolls.
In any event, I'm curious if other people have had experience with this hack, and what downstream effects it had. Obviously damage bonus shticks have a larger effect, but also the shticks that lets you just drop an opponent in the 3rd sequence become less useful when the 3rd sequence is less likely to happen, Reload Checks become less onerous when there isn't a 3rd sequence to the fight. Are there other things I'm missing? And if you did do it, how well did it work?
45-60 minutes seems a little long, but scene length is going to vary from group to group. I'm curious whether the whiffing is worse against mooks or Featured Foes?
But yes, adjusting the combat values to fit your particular group may be required, particularly if you're adapting some of the older 1E scenarios, where the AVs and number of enemies can vary widely. As a slight variation on Robin's suggestion, similar to what happens with some of the Supernatural Creature powers, you could incur a -1 penalty on the enemies after each sequence. You could also try a "Tide of Battle" mechanic, where if the PCs are doing really well, or if certain events happen, one side loses "morale" and incurs a penalty, or one side gets a bonus for "inspiration". If a Boss or Featured Foe gets taken down, the remaining enemies could lose some confidence or start looking for the exits.
Particularly if the PCs have whittled down the opposition to a few remaining enemies who are now outnumbered, I think that's plenty of justification to incur a -1 "morale" penalty.
In a way I've tried it out, in the form of bosses who can lower PC defences as a special action. If I recall was like -1 Defense on the target for the rest of the combat for 5 shots or something like that. After a few of these the characters were a bit more receptible to enemy attacks.