Combining characters work poorly with macrons and breves

[The1CannedMan]

When writing Latin, indicating the arsis of each foot (in poetry) is preferably done by adding U+323 under the letter, or by adding an acute accent if prose (usually for teaching, such as Wheelock’s). Example:
Poetry: sị̄c onus ịnclūsụm numerọ̄ distị̄nxīt eọ̄dem
Prose: Égo ómnī offíciō ac pótius pietā́te érga tē céteris satisfáciō ómnibus
When using the combining dot below (U+323), the tittle over i-s is redisplayed and the macron superimposed, rather than being a plain i with macron and a dot below; when using accents over the macroned letter, the macron is superimposed over the breve, rather than floated above.

Settings and system:
Win 10 x64 version 10.0.17134.590
LibreOffice version 6.1.2.1 (x64)
Font and its details: EB Garamond:liga=1&dlig=1

[Edit]
The same issue applies to the breve:

[Edit]
Further, when adding a dot to an æ, it is misaligned, centered below the a-part of the æ, rather than in between where the a- and e-part connects; and when adding it to an å, the ring for the å moves slightly to the left, as can be seen in the image below.