If you've a large discretionary income present, it's fine to lump sum since the funds are available. Personally, I wouldn't lump sum with everything at once. I'll like to divide the money into 3 parts, lump sum with the first part, use the second part to increase my aggressiveness in DCA and keep the last part for buying my target dip.
So I did lump sum some time back, but personally I feel now (hindsight?) that splitting the same amount into a DCA would have been a more effective approach.
I bought in Nov '24, as a lumpsum. Then in Jan/Feb I was happy but in Feb we got a bit of a dip - right up until April.
Conversely if I'd done a small amount in Nov, then bought DCA below my last buy price I think I'd have made a bundle more.