If you have big hands like I do, you definitely need to be careful with those cheaper fixed grips. I tried the Haoge THB-X100V Thumb Rest for Fujifilm X100V and it basically made the rear command dial useless for me. I was constantly fumbling and missing shots because I couldnt get my thumb in there properly. In my experience, the fixed ones feel cramped on the X100V body. Heres how those options stack up:

• Lensmate Folding Thumb Grip Fujifilm X100V Silver: This is the one to get. The folding hinge feels super solid and it actually clears the path for your thumb to hit the dial without shifting your grip. It makes the camera feel way more secure when you are walking around for hours.
• JJC Soft Shutter Release Button Set with O-Ring: These are fine for the price. They come in a pack of two, which is smart because you might lose one eventually anyway.
• Squarehood Mini Soft Shutter Button Brass: These look way better and the thread quality is usually tighter, but they are pricey for such a tiny part. Make sure to use those little rubber o-rings that come with the buttons. They act like a lock washer to keep the button from vibrating loose, but be careful not to crank it down too hard. You dont want to strip the threads or mess with the shutter feel too much. I would suggest grabbing the Lensmate and the cheaper JJC buttons. That way you put your money into the ergonomics that actually keep the camera in your hand while you are exploring Tokyo. Just be sure everything is tight before you leave your hotel every morning... losing a button on the first day in Shibuya would suck.

To add to the point above:

• get the SmallRig Thumb Grip for Fujifilm X100V to save cash.
• in my experience, plumbers tape ensures the VKO Soft Shutter Release Button Brass doesnt fall off.

Late to the thread but I wanted to mention the potential for mechanical stress on the shutter assembly. Be careful with those tall buttons; if they snag on your camera bag liner, they can actually bend the internal post. I usually suggest the Komaru Soft Shutter Release Matte Silver because the profile is lower and the dual-contour design gives better tactile feedback without needing as much downward force. It tends to stay on better than the cheap ones because of the thread tolerances. For the thumb grip, if reliability is the main concern, skip the folding ones. Moving parts are just failure points in the long run. I would suggest looking at the Match Technical Thumbs Up EP-2V for Fujifilm X100V Silver. Its solid brass and the fitment is basically perfect, though it is definitely a premium price point. If you really have large hands tho, a thumb grip alone wont fix that thin feeling. You might want to consider the Metro Case Hand Grip for Fujifilm X100V instead. Its super light 3D printed nylon and actually gives your fingers something to wrap around. Much more secure for street shooting in a crowded place like Tokyo than just a thumb rest.

+1

Quick reply while I have a sec. Honestly, I have been through like four different X series setups over the years and the ergonomics always bug me at first too.

• Just go with anything from Lensmate for the grip. I know the price tag is annoying but that hinge is the only way to live if you actually use the dials. I tried a cheap fixed one once and it drove me crazy within an hour because I could not reach the back dial properly. It just felt cramped and awkward for street work.
• For the button, honestly just get whatever from Squarehood. They look the best and the quality is solid enough that you wont be disappointed.
• My big DIY tip: skip those tiny rubber o-rings and use a tiny bit of PTFE tape—the white plumbers stuff—on the threads. I learned that the hard way after losing a custom brass button in a gutter during a shoot in the rain years ago. Since I started using the tape, nothing has budged. Ngl, the silver on silver aesthetic is worth the extra few bucks anyway if you want it to look clean for your Tokyo trip... you will thank yourself when you are looking at the photos later.

Yo, congrats on the X100V! Id be super careful with expensive buttons tbh. Since you are on a budget, check out the JJC TA-X100V Thumbs Up Grip. Its way cheaper than Lensmate and does the job. Definitely use those tiny o-rings for the JJC SRB-B10S Soft Shutter Release Button tho, or itll unscrew and vanish in two days. Just dont overtighten it because you could damage the shutter mechanism... thats a nightmare fix.

Lol I was literally about to post the same thing. Glad someone else brought it up.