I said no, because I believe it is impossible to semi-bluff appropriately without being able to correctly and consistently read hands and read players.

If you can't read players, you can't choose the right tables. If you can't read hands, you won't know when to bet, bluff, semi-bluff, or make that tough laydown.

Changing gears is also irrelevant unless you have a reason to do so, based on your read of your opponents. If you have been (semi-)bluffing a lot, some will notice, some will not. In the hand you are in at the moment, against this opponent, have they noticed you were (semi-)bluffing a lot? If not, get on with it. If so, you have to consider changing gears; which brings us back to people reading being a more important skill overall.

Without the ability to assess your opponents and their hands, the rest of your tools (semi-bluffs, value bets, bluffs, etc) may very well be completely off target on a regular basis.