It has been noticed, but it won't be implemented at this time - not because we do not want to try it, but because it has already been thought about, tested and tried and did not yield the results commonly claimed. We are aware of your concerns, but that does not change the current situation, so the answer is still the same. Until there is a completion of vehicle trees (or near completion) a reduction of BR spread isn't practical. And even then it will still need further investigation before it can be implemented.

We tested the smaller spread system during the 20 rank system and also enabled 2 rank matches for jets at the time. This already provided us with good data to analyze the situation without enabling it for all.

Yes, it could be tried again, but by doing that before (near) completion of vehicle trees, we would be in danger of discouraging a great amount of players who do not have an issue with the current spread and are not fully appraised or even interested in hanging around in queues for longer. Also, while a spread reduction might be beneficial for some vehicles, it will also cause worse MM for others - so reducing the spread now would not be a “fix”, but rather a trade-off.

BR spread and MM are integral to our game of course and are always the focus of development attention, despite the assumptions, it isn't an easy procedure to improve and we will continue to strive to find the best solution for the majority.

Queue time will be exponentially greater (less pronounced in lower brackets, likely unplayable in higher brackets) - the Matchmaker will have less vehicles to choose from.
There is no pronounced extra difficulty between 0.7 and 1.0. Vehicles in our current BR range can effectively combat each other.
Some vehicles would always be matched at the highest spread, as the MM would not have enough vehicle to choose from to make it “even”.
Many vehicles would become unused, many vehicles would become flavour of the game, this would not be a good situation at all.
Battles would become less diversified as especially on the higher ranks it would be only the same few vehicles fighting each other - but not only there, also in lower rank matches.
A “Quantitative” MM will allow better fine tuning of encounters and improve battle fairness and is a better alternative, as it is not as restrictive and does not come with the negatives of spread reduction