As long as you put the alternatives clearly on the table, you could let the customers choose, and sign off on taking the risk. You can give a recommendation, but ultimately it's their choice if they bear the consequences resulting from the choice.
Eh, letting the customer footgun never comes off well. They will always fundamentally blame your advice or lack of advice.
Hard disagree. Framing it this way makes it seem like all possibilities are equally valid options. Yet you’ve somehow winnowed the field of infinity to the several options presented. You did that through successive rounds of professional judgement that eliminated options you did not consider fit to propose.
Taking options off of the client’s table is the core responsibility here.