The great advantage of basal - bolus insulin regime is the flexibility to eat as often as you want.
If you want to skip breakfast, no problem. If you want afternoon tea, go for it.
It may be described a "4 injections a day" but this is a simplification.
It is one injection every time you eat a significant amount (usually more than 10g) of carbs plus once more.
So, whether you have to inject when snacking depends on what and how much you eat.
Cheese - no need to inject. A Rich Tea biscuit - no need to inject. A couple of Jammie Dodgers and you will need to get your insulin pen out.
I started on a fixed dose of two injections and hated the restrictions it put on my eating.
As soon as I changed to basal-bolus, I was back to my usual eating (grazing) patterns again.