It is still difficult to believe that Canon does not offer a lens (as opposed to filter) adapter for the G1X and that third party manufacturers, Lensmate in particular, have not developed their own lens adapters.
To mount their macro flashes MT-24EX and MR-14EX to the G1X, Canon offers an accessory, the Macrolite Adapter MLA-DC1. Although I do not have the macro flashes, the MLS-DC1 looks enough like a tubular lens adapter that I decided to get one and hope to find some use for it. Actually, instead of the Canon product, I got the cheap clone JJC Light Adapter MLA-JDC1 shown above. It is simply a tube with bayonet adapter to fit the G1X and a groove to hold the Macrolite flash.
For my G9 and G12, the lens adapter also provided protection for the lens and a gripping point while shooting. The MLA-JDC1 is sturdy enough and offers some protection for the lens but the bayonet protection ring on the G1X is wide enough to wrap my fingers around it so the MLA-JDC1 is not needed.
I do have a macro LED light that fits my G12 via the Lensmate adapter 58mm filter threads. Although this macro LED light would physically fit the Lensmate filter adapter for the G1X, there’s no way that I would hang it on the end of a collapsible lens. Instead, the LED light can be “adapted” to the MLA-JDC1 with gaffer tape (never leave home without it).
This adapted configuration is awkward but it works; that is, it sort of works. The LED macro light is not bright and must be close to the subject; however, the G1X is macro challenged and really needs the 250D close-up lens. Unfortunately, the 250D requires a filter adapter and that filter adapter is larger than the bore of the MLA-JDC1. This means that the G1X lens could not be retracted into the MLA-JDC1 (and, I assume, the Canon MLA-DC1 as well). I wouldn’t use the combination of MLA-JDC1 and a filter adapter for fear that the G1X would turn off and damage the lens.
Yet another reason for keeping the G12 for macro work.