This puts it on par with the pace of 1809 one month after its re-release. And this is, probably, not a good sign as we've seen how this ended (just over 30% install base before the next release went out).

Now that the Feature Update is optional in both Home and Pro that doesn't come as much of a surprise. After the experiences with 1809 who can blame users from being cautious? As 1803 nears 'end of supported life' I'd expect Microsoft's automatic 'pushed' update to kick in and boost that take up rate.