best use of tier 5 catalysts

DP79

Hi all,

Trying a poll since got no feedback on my question. Maybe a poll will get something to help me decide.

Uncollected player here but have been stuck for a long time. I usually clear uncollected monthly quest using boosts as needed, try not to use units for revives. I feel I have a strong top end roster

Since tier 5 cats are so rare I want to make best use. Whether going r2 on 6* or r5 on 5 star
I have been waiting a long time for an r5 or r2 so want to get it right. And hopefully push for cavalier

Thanks all