Yes, the Klein Tools Line Splitter can be used with clamp meters from other brands.
Only the appliance load at the out it's plugged into. This is not the entire circuit as measured at the breaker. Use a loop style clamp on meter at the panel to do that. Do not do this unless you fully understand the dangers lurking inside your breaker panel uncovered.
Your probably clamped onto the ×10 part of the splitter or it only reads that way . This is used for low amperage so the meter can make an accurate reading. So if its reading 49.1a its actually 4.91a. I made the same mistake in my early years, hope this was helpful
I have 6 Home Depot's within 45 min driving time from my house and they all carry different items, when I asked the store managers why, he said that different items sell better in one location than another & it's up to the store manger what to put on the shelves. Each store most likely has a limit as to how much inventory they can have on hand, so that might play into it as well.