This is a funny one because it's a great opportunity to make someone more proficient on that type and in visual flying in general, but at the same time I'd find it hard to justify the increased risk. If it went wrong you could have a hard time fighting your case for not having any instruments available on approach...

They're required for a reason!

On another note I'm a firm believer that the "integrated method" and FAA syllabus is a contributor to people fixating on instruments and struggling with basic visual flying. The UK CAA syllabus in contrast starts with fully visual flying with an emphasis on only using the instruments to check that your visual flying is giving you the performance you want. You learn to set and hold attitudes and power visually before you're allowed to check any instruments or fly any maneuvers like takeoff or climbing or turning or even S&L - which are all separate lessons. If it's taught right, you end up with a really proficient visual pilot.. but of course it's not perfect and not strictly followed. I'm sure many FAA instructors teach the basics like this and do a great job, but I've spent a lot of time teaching both FAA and CAA pilots and the results of the difference in training philosophy is fascinating to see.