Without very good reason to recommend BPR schemes (i.e. serious ill health, reduced longevity) there's little reason to recommend a BPR scheme. They are excellent in cases where IHT planning has been left uncomfortably late, but they are extremely expensive, produce meagre returns and are high risk. For example, just surviving the two year anniversary isn't enough as the 'test' for BPR qualification is done at the time of death and not guaranteed. That being said, if you're saving £800k in IHT as the trade off for that, they can be very good as in addition to the potential tax benefits, you retain control of the capital and can withdraw ift if you need to, albeit with reduced liquidity.
I've had some mega wins for clients with Octopus and Blackfinch in the past because they made absolute sense to use them and gave massive savings to the estate. But if you're young (i.e. <60) and don't have any serious health or longevity concerns, it would be difficult to justify using BPR over some kind of straightforward gift or trust arrangement.
Pay tax all your life on your income and savings, only for your savings to then be taxed again when you die is a pretty lame argument imo.