...can MacOS 10.13.5 be far behind?
I guess I hope not.
Actually I am already running MacOS 10.13.5 beta 1 (and iOS 11.4) — the MacOS 10.13.4 golden master was barely a week old when 10.13.5 was released to beta testing. FWIW 10.13.5 has been remarkably problem free — only one app, Airport, has evinced any problem and that problem appears to me to be due to a build control issue on the developer's part and nothing to do with MacOS.
Unless the 10.13.5 beta is unusually short I think it is a tossup whether the next release will be 10.13.6 or 10.14 or the 10.13.6 and 10.14 betas will overlap one another.