It's up to Avera to order that feature to be included in Sentinel-EU and the EU firmware, if they want to pay the cost for the implementation. US scanners doesn't get dPMR and extended frequency coverage that EU scanner has but I would guess that Avera would like to have the waterfall and improved decode quality for the EU models, if it has been enough of them sold. But usually Avery have waited until a new feature have matured and any bugs been fixed before they will offer any upgrades to EU users, so it will be at least a months waiting time.
Maybe Butel will let us know when he gets a beta version to test with his programs, and an upgrade can be done from his website to ARC536.
Butel have an interesting text at his Facebook page, that Avery presented the waterfall feature in a september show. Avera only distribute the EU versions of SDS scanners.
"Uniden has released new firmware for the US models SDS100 and SDS200 thru Sentinel that includes the waterfall option that was annouced at the Avera event last september. There is no news yet about a new release for the E versions."
/Ubbe