Some of my container plants have fairly narrow pH tolerances and some have very wide pH tolerances; see examples below).

Is it better to stay on the low-end or on high-end of the range or to split the difference?

Plant pH tolerance difference
Euphorbia milii (Crown-of-Thorns) 6.1 to 6.5 0.40

Camellia japonica 'Kramer's Supreme' 5.5 to 6.5 1.00

Azalea 4.5 to 6.0 1.50

Protasparagus densiflorus 'Meyeri' 5.6 to 7.5 1.90

Tecoma capensis (Cape honeysuckle) 5.6 to 8.5 2.90

Prunus cerasifera (Purpleleaf Plum) 4.5 to 7.5 3.00

Lantana camara 4.5 to 8.5 4.00