Thoughts on 50% index covered call ETFs – QYLG and XYLG?

Downside of pure covered call ETFs – such as QYLD – is that they sell covered calls ATM on the full portfolio which means your upside is very limited.

QYLG and XYLG are covered call ETFs for Nasdaq 100 and S&P 500 but they only sell covered call on 50% of the portfolio. Thus, it seems to have a good balance of selling covered calls so you get a heightened dividend income relative to the index itself , but also leaves room for more upside as 50% of the portfolio is not capped with covered calls.

Curious if anybody has any thoughts on these, particularly downsides.