Should I pre plan for my dad's cremation?

If your dad is able to help make some of these decisions let him help you make the plans. With his direct involvement his siblings can’t say these were not his wishes.
Most funeral homes also have a crematorium so you can deal with a funeral home or contact a crematorium yourself. Many will come to the house to make things easier.
If dad does not want to be involved and you already know his wishes then go ahead and plan and even pay for the services you want. Less likely they will try talking you into “extras” later.

My dad was cremated. I used the funeral home he chose for arrangements. They were extremely helpful. They provided many of the details I didn’t think of regarding cremation. They didn’t try to up sell or cross sell any services or products. They made it a stressful time very seamless.

Going thru a funeral home may help in some ways. Like said, picking up the body for one. But no need for embalming or getting body ready for viewing. The funeral home will contact Social Security of the death and supply the death certificate. Mine supplied me with 10. Of course the cost was included in the price of the funeral. With my in-laws, the crematorium and funeral home were one and the same. So we had no problems there.

I would check both out. What the crematorium will do and what a funeral home will do. With my Mom, we used the funeral home to set up a prepaid funeral trust. It was a separate company so I didn' need to use it just for that funeral home.

I prepaid, and when LO was diagnosed, the funeral home was an enormous support in preparing me with what to do.

By the Grace of God, LO recovered, and when I told them we’d be a while longer before using their services, they rejoiced with me that her health had returned!

I found no disadvantages to prepaying.

I went through a funeral home to prepay for my mothers direct cremation. The funeral home rep was able to guide me through the state’s rules and regulations regarding the possibility of needing to plan for Medicaid in the future. Every state is different. The rep also educated me on expenses I hadn’t even thought of, such as picking up the body, storage, containers, obituary, death certificates and other fees, and I was able to pre-plan for these expenses using her funds, all while following the appropriate guidelines if I need Medicaid for her in the future. I wanted to prearrange everything ahead of time for several reasons. I wanted to make sure funds would be available. I didn’t want to run around at the last minute or make calls in the middle of the night to find a funeral home. I was able to meet and be comfortable with the facility that would be handling my mothers final arrangements. I was clear headed and relaxed when I made the prearrangements. And now, it’s done - the paperwork is all ready and it’s one less thing I need to stress about.

Your question: "My question is should I pre plan his cremation by contacting a crematorium directly? "

I found this link that explains what a funeral home will do, and what a crematorium will do. Under crematorium, I didn't see "picking up the body" as one of the services. Be sure to confirm this or else, you might have to deliver the body to them. Eew!!! I don't want to save money on that service. But yes, working directly with a crematorium will cost less.

https://www.oneworldmemorials.com/pages/working-with-funeral-homes

My step Dad and my Mum have both prepaid for their cremations through a local funeral home. When my step Dad was dying I called the funeral home to confirm what the procedure was for when he died and if he died at home or in the hospital. When he did die a couple weeks later, I had the number to call in my phone and they came to get him.

We met with the funeral home people a couple days later. David had a memorial service at his Church. Because he was cremated we waited 10 days, which gave time for out of town family to attend.

I also helped to organize an uncles cremation about 18 years ago. I can confirm that it is far easier to have to planned ahead of time, whether or not you plan to have a service.

This was my brother's wish, as well. Hospice gave me the names of several trusted services and I found it quite inexpensive and easy to do. I live in expensive Calfornia but the costs were approximately 2,500. It would have been a good deal less in that I ordered way too many death certificates. I was told that many entities wanted an original. I did not find that to be true. Banks made copies and handed me back the original and many placed accepted my copy of same (credit agencies I notified, and etc).
If you wish this paid now out of Dad's funds, then certain do call in your area and pre-arrange. There is no reason not to.

My opinion is yes to pre-pay. The reason being if he is a Medicaid recipient he is allowed to use up to a certain amount towards that without penalty. If he is not a Medicaid recipient it is still a good idea so that it's taken care of as his assets get used up for his medical care and housing. This is something your father's durable PoA can do for him.