Steep and vertical downhill chainlift buildable without cheats

Operating System

Windows 10 64 bit

OpenRCT2 build

OpenRCT2, v0.4.18 (68789ec882 on develop) provided by GitHub

Base game

RollerCoaster Tycoon 2

Area(s) with this issue?

This is a development issue

Describe the issue

Roller coasters can build chain lift on steep and vertical downhill track, even when the All Chainlift cheat is disabled, on rides that do not have sprites for these chainlifts.

Down25ToDown60: chain button is enabled and works.
Down60: chain button is enabled and works.
Down60ToDown90: chain button is enabled, but clicking it does not toggle it on.
Down90: chain button is enabled and works. Chain is toggled off when switching to this piece. Chain is not toggled off after building.
Down90ToDown60: chain button is enabled and works.

Tested with giga track and B&M track.

Steps to reproduce

1. Build a coaster with vertical slopes, without the chainlift cheat.
2. Chainlift can be built on some vertical slope down pieces
3. Chainlift can be built on some steep slope down pieces

Attachments

No response

No source file, test, or entry point is named. Reproduce the issue with the chainlift cheat disabled on giga and B&M tracks, checking the listed steep and vertical downhill pieces; done means unsupported chainlifts cannot be enabled or built on those pieces.