I have never played a Burns folkflute, so I am not able to compare or contrast them with the PVC flutes that I make. However, I can add to the comments about my flutes.
For one thing, the hole spacing on cylindrical bore flutes needs to be farther apart than on a conical bore flutes in the same key. To compensate for the larger finger stretch, I compress the finger hole spacing by alternating the size of the finger holes. This results in three different hole sizes, with the smallest hole having a diameter of 5/16” and the largest hole having a diameter of 7/16”, which is a pretty large finger hole. Larger finger holes are a little harder to cover, but the good qualities of large finger holes are that they are easier to half-hole, produce loud and clear flute tones, and make slurs easier and more expressive. Consequently, I recommend my low D flutes to those with at least average, adult-size hands. For anyone with smaller hands, I recommend flutes with conical bores or shorter flutes in higher keys.
One difference in my flutes and wooden flutes with a simple joint between the two pieces is that the tuning of my flutes, with a two inch copper tenon, can be changed significantly. In fact, the tuning can be raised or lowered nearly a semitone from standard pitch, just in case you are trying to play with an instrument with fixed tuning that is off pitch.
With regard to the cutting of the blow hole or embouchure, the chimney depth on my flutes is 3mm, which I believe is sufficient to cut a very good playing embouchure. The small round blow hole of 3/8” diameter does require a focused embouchure, but the smaller blow hole is essential for playability, since the bore diameter is a large 21mm, whereas the conventional silver flute has a bore diameter of 19mm. By my reasoning, larger bore flutes play better with smaller blow holes.
Another quality of larger bore flutes is that they tend to favor the first octave. The first octave can be loud and easy to play, and the low D can really boom out. However, with a good embouchure, the second octave on my flutes comes in easily, and I can also play several third octave notes without difficulty.
The tone that you get from an Irish flute is going to depend mostly on your embouchure. Turning the blow hole towards you, and playing the first octave notes right near where they are ready to break over into the second octave, produces the complex, woody tone, rich with overtones, that most people are looking for.
And lastly, in addition to the larger finger hole spacing required, another limitation of cylindrical bore flutes is that the upper part of the second octave tends to go slightly flat unless you blow in the notes, which isn’t very easy for a beginner to do. I have recently designed a small wedge, which is inserted into the flute and rests against the stopper, which compensates for this problem. The wedge also makes the overall tone of the flute less loud but more complex and woody. I talk about it on my website, if you are interested, and I hope to have a sound clip available soon.
Best wishes and happy fluting