That's the nature of software development. Its not like a well run commuter railway with updates arriving on your computer every few minutes. The next update, be it another beta, the first release candidate or (less likely) the final finished update, will arrive when it arrives.
Trainz Plus TLR Phase 1 and TRS22 SP3 Update went live just minutes ago. Contrary to my statement in the above post they skipped the Release Candidate (that's the nature of software development). Downloading my copy now (9.3 GB). Details are at Trainz-plus-tlr-phase-1-trs22-sp3-update.175710