I think you're asking in the wrong place. This is the 'Classic Menswear' section of a forum dedicated to 'style'.
The term 'cosplay' is an abbreviation of 'costume play'. I'm not going to make any value judgements on whether you should or should not wear it, but the term implies it's not intended for everyday public wear.
Is anyone else finding the recently-introduced marketing copy on Luxire's blog somewhat over the top:
"Having or ordering a denim shirt is the best thing you have ever done. They will always make you look good, cool and classy."
If it's going to bother you, which by implication it will since you took it to the tailor, get it tailored.
He is right, it will likely leave a visible mark.
If you are paying to do so, do it properly from the shoulder so you retain the original finishing to the cuff (assuming the shoulders are finished in a way that allows this).
Another way to look at it - if fused is the only construction technique offered by the tailor then walk away. If they offer a fully bespoke pattern with fused construction as a lower cost option against fully canvassed then it can be a means to dial in your pattern or experiment with fabrics with less sunk cost.
This. Although if you are set on keeping them, analyse where they are too large. Insoles reduce depth and therefore overall volume. Heel pads address a heel cup that is too large, and tongue pads a shoe which has a lasted instep higher than your foot.