I think that having slightly longer updates makes for a better reading experience, but a lot of folks opt to simply post what they can put out weekly, which for a lot of folks doing comics on the side and/or as a hobby is ~1 page per week. There's not a right or wrong way per say, but I think epsides of the length you're suggesting (~±3 pages) are nice.
for this though:
I... think this is a case of "no, it won't". Not entirely sure and things may have changed recently but I always think back to this thread:
At the very least it doesn't show up in your Subscriber's bookmarks (so people on the app wont see the update to the episode at all) but I wouldn't be surprised if it didn't "re-Fresh" your series either.