I'm not sure about what is meant by forcing a technique when they tell you to "slow it down." When I say slow down it is usually related to control. Sometimes students will try to do things faster than they are able to handle and as a result technique falls apart.
For me forcing a technique is not about the speed or the power. It's more about using a technique that doesn't work natural for the position that they are in.
For example, I would have been screaming at Victor Moore (0:36) mark for trying to parry a punch starting from his waist. He was forcing a technique that was never designed to be used from that position.
I would have yelled "Do we train like that in class? Then why would you stand like that with your hands to the side and expect it to work." lol. He would have a long 2 hour lecture about something that only takes less than 2 minutes to understand. If Bruce Lee told him to stand like that, then he should have said. Nah bruh!! It don't work that way. lol
I don't think I've heard of "technique forcing" as something that relates to "slow it down" is that related to muscling technique? When I hear slow it down, it's usually because someone is trying to do a technique faster than they are capable of doing. The faster someone goes the more likely a technique will fall apart. So speed and technique are often trained with the goal of being able to go fast without destroying or short cutting technique.
What is usually happening when they are saying "slow it down" are they doing forms or is someone punching too hard?