canoe has a "code" (or whatever they're called, im not really an expert) that is set on games that use hi-res mode, maybe setting that would help if the game doesnt' originally use it. The canoe fixes thread had some talk about that with some games that had issues.
Unlike the aforementioned Seiken Densetsu 3, Tenshi no Uta does NOT use hires, so it's to be expected that fiddling with those presets will do nothing about this particular issue. The translation does, however, expand the SRAM to use it as extra RAM for variables, vwf scratchpad etc. An extra 8kB of known free RAM is really nice on the SNES. Nightcrawler's previous translation, Glory of Heracles IV, does the same thing, but with no such issues. So it's not like this approach is flawed. Like I said, it's just that the expanded SRAM happens to be incorrectly mapped in some older emulators, as well as the Super Everdrive. The translation does work on real hardware, as well as more accurate emulators.
For the record, there are only a handful of translated SNES games using hires. The ones I know of are: Seiken Densetsu 3, Rudra no Hihou, G.O.D. and probably Marvelous.