Option to purchase family home for a minor in a will

A will client would like to include an option to purchase the family home for the youngest child, who is currently a minor. This is not something that we have previously included in a will and having looked at some of the precedents on Williams on wills etc, there are clearly a number of considerations for the testator before the clause can be drafted. In terms of the current situation whilst the child is a minor, I am not sure that this would be workable. I am minded to advise the client that it would be advisable to draw on specialist expertise when including such a clause within a will however am not sure if I am overthinking the potential problems. If this is something you have dealt with before, I would be interested to hear about potential pitfalls and whether this is something that other will drafters would draw on expertise of property/contract specialists for when drafting such an option within a will?