Not all bespoke shoemakers do a trial shoes for fitting purposes.
JLP do, some Japanese makers do. But both JL St James and G&G do not. It's all about their house workflow.
Not sure about Cleverley, better to ask their opinion.
p.s., tough to fit is usually a RTW phenomenon; and cap toe is harder to fit than plaintoe/wingtip/etc due to the toe cap stitch/stiffening.