Say I do a Tipple along the LoD with the intent of following it with a chasse reverse then a progressive chasse progressing along the line of dance. The tipple leaves me stepping with the right foot but the CR starts with a left foot so I must insert a right foot "slow" step here which I have heard called the "bridge" step. However, I cannot find this in the Ballroom Technique (which also seems to disallow the tipple preceding the chasse reverse). I have been told that the IDTA (is this abbrev right?) specifically allows the bridge step, but I've not actually checked.
My real question is that if I do the above sequence in bronze competition am I likely to be invigilated?
The "bridge" step you wrote about is not in fact a separate step at all, but legitimately the last step of the previous figure. Don't forget that the last step of the Tipple, as well as most figures that end similarly, is a forward step on the man's RF, outside partner. We've coined it the "overlap" step, as it often represents the first step of the following figure, but it doesn't have to. There are examples of follows to these figures in the ISTD Technique book where they don't overlap, but rather start the next figure with the man stepping forward on his left foot. In these instances, the last step is not treated as an overlap.
For example, a Progressive Chasse is a figure whose last step is RF forward in CBMP, outside partner. In most cases this is an overlap, as most follows are natural figures (e.g. Natural Turn, Natural Spin Turn, etc) that begin with the RF forward. However, a Quick Open Reverse, which is a reverse figure commenced with the man's LF, is also listed as a follow. The stipulation is that you must be traveling down LOD or toward DC, so you'll either need to take your Prog Chasse with 3/8 turn, or dance the version that moves across LOD following an Impetus or Spin.
The Chasse Reverse Turn is a slightly different story. In theory it should work approximately the same, and so one would expect to see it listed as a follow in the technique book. I suspect that they left it out because it's a more difficult follow, suitable perhaps for silver/Licentiate -- although if it were me, I would have included it with the stipulation that the combination itself be saved for silver & above. Maybe they figured if you're in silver, you're going to replace the Chasse Reverse with the Quick Open reverse anyway. Who knows.
At any rate, if it were an acceptable follow, you could not dance the combination starting with a Prog Chasse moving along LOD; Such a combination would require a half-turn either over the preceding Prog Chasse or the following Chasse Reverse. Either one would produce a Viennese-style crossing action, which takes it out of syllabus. Your only choice would be to precede with an Impetus or Spin so that the Chasse moves across LOD and finishes with man facing DC.
Similarly, the combination you mentioned beginning with a Tipple would need to be underturned to finish with man facing DC, so that the Chasse Reverse is taken with the proper 3/8. Otherwise you're going to have the same problem with the crossing, which is definitely out of category.
As to whether you'll be invigilated at a comp, that of course comes down to the invigilator. He would need to have eyes like a hawk to even notice it, and even if he does, it's questionable whether he'll call you out. Technically both figures are allowed at the bronze level, and as I mentioned, the extra step is not extra at all -- It's part of the Tipple. The only way it could be considered out of syllabus is if the invigilator is adhering strictly to the precedes and follows as prescribed by the ISTD technique book.
As usual, when asking yourself whether or not to push the envelope, the best answer is probably "no". You can probably get away with it, but why bother? The advantage to such a combination is so minimal when compared with the potential liability.
In American style pro-am, there is a sort of pressure to push the envelope because the advantage to doing so is much greater. But if you're talking about the difference between a Prog Chasse to DC followed by Chasse Reverse Turn and a Natural Hesitation followed by Chasse Reverse Turn, it's just too small to get worked up over. If you really want a kick-butt bronze combo that flies down the floor as fast as most silver combos, why not try this instead: Chasse Reverse Turn, Reverse Pivot, 2 Double Reverse Spins, Prog Chasse to R., Back Lock and Running Finish.