I am not sure what would be new about the band-width issue.
For posts, there are two ways to put in images: a) as an attachment (current limit is 5) and b) as an IMG link (currently I don't know of any limit). When most desktop applications go to a thread, it seems that the attached and linked images are all uploaded in the batch of 10 posts. That can be a lot of images per 10 post batch, such as Midwest Drifter's Australian travelogue is currently doing (
https://sprinter-source.com/forum/showthread.php?t=53190&page=27). So bandwidth may be related to location of the attachment. Attachments are presumably located on the same site as the rest of the forum; whereas the IMG links can be anywhere. If "where" an image is located infers bandwidth, then the forum may want to encourage the use of forum-based albums to "store" those images. If location is not an issue, but bandwidth is, then that implies the number of linked images need to be limited.
Forum-based albums are incredible awkward compared to other photo dump sites. These are not substitutes for dedicated photo sites such as Google's Photos. A forum based album serves largely one purpose as far as I can tell - if the images are linked into threads of the same forum, then the likelihood the link will be broken is significantly diminished. Once uploaded, these albums' inventories do not create a bandwidth problem. So I don't see the issue of the number of image limitation on albums creating a bandwidth issue unless there was some ability to mass up- or download files. I don't see either of those as options - and I do not propose that given what I see as the main purpose of the albums.
I do not see many people using the album option, so I do not believe that a numerical limit means much either in terms of storage space or bandwidth. How about 500?
With regard to upload limit into an album, the current limit is 3. I would suggest at least match the post limit of 5. 10 would be nice - but there is some computational time involved as album uploads also resize pictures to max of 600*600.