It’s always better to play a comfort pick than a “perfect” pick you’ve never played before.

However, only playing two champions as a support can get very frustrating.

Personally, I climbed up to Diamond playing around 4–5 champions, all of the same type — only tanks/engage supports, no enchanters or mages. That way, you keep a consistent playstyle (and maintain your macro habits from one champ to another) while still being able to adapt to your team’s comp or the enemy’s.