Converting Matcha Tins into cups?

I was thinking of buying or purchasing cylindrical glass tubes with flat bottoms and sliding them into the tins as liners

Certain brands like Yamamasa have smooth internal walls so there might be less work needed (if not none at all and we could use it as cups straight away?

Some like Marukyu have seamline running vertical and it seems maybe the walls are not a smooth singular diameter as there seems to be internal flanges making it nearly impossible? (i have never had Marukyu from a tin but only the bags so i dont know and its hard to judge from images online, can someone confirm?)