The import.meta.url will blocked in worker because of the null point of document in the build result.

[fishel-feng]

I am encountering an issue where if the original package uses import.meta.url, the resulting bundle will access document, which causes a null pointer issue in a worker. Which making the build result of this plugin unusable.
This issue has been fixed in Rollup's UMD build but not in IIFE rollup/rollup#4186
I want to know why IIFE was used for the build instead of UMD format. Is it because the resulting bundle is smaller?
I'm not sure if this is a valid use case for Rollup, but it is blocking my program. If this issue requires support from Rollup, I can submit a bug report.