DGT query

Hello,
Planner wants to set out 3 scenarios for a client who is concerned about IHT and needs an income.
1. Keep £1m in cash in his name earning 4% interest and him drawing £8,000 pm from it
Vs
2. Settling £1m into a DGT with the trust owning an OB keeping the money in cash earning 4% pa and him drawing £8000 pm
Vs
3. Settling £1m into a DGT with the trust owning a GIA keeping the money in cash earning 4% pa and him drawing £8000 pm.
Transact's DGT calculator suggests that client might get a 70% discount if he put in £1m, so that would get the gift part under £325k to avoid 20% lifetime IHT.
£8k pm is 9.6% withdrawal rate, with excess over 5% being taxed on the settlor (UK res) under chargeable event rules with the OB.
I've not seen DGT's set up with a GIA before, the usual wrapper tends to be a bond. Are there any reasons or downsides with this, apart from greater reporting requirements for trustees with a GIA? The GIA wouldn't come with the same limitations on withdrawals.
Struggling to find any guidance online, if anyone could share some thoughts?
Thanks.
Comments
I think there's several things at play here
BUT!
The sample deeds are drafted by bond providers! Not sure I've seen a platform offer one.
I thought that might be the case. If I’d never seen a GIA/collective facilitated with a DGT before there must be a reason!