Using a speed map in a post application will give you the option of a couple of ways to modify the relationship between the individual frames -- three main approaches; "Nearest" "Blend" and "Optical". They will all yield a slightly different feel to the time progression. You may also derive a benefit from using a de-flicker filter which may not have to cope with abrupt lighting changes. A true time-lapse with an intervalometer of course is frame-for-frame which is data-density efficient. If that is not a concern, and the expense/investment ratio is now very different from when we were paying for film stock, I'd shoot real time or at a ratio not as dense as your final. If you have to perform fixes or cleanups with individual frames, you will have the option of something adjacent to your select frame to pull the "heal" pixels from.
"I always pass on free advice -- its never of any use to me" Oscar Wilde.
Shooting real time and manipulating later gives more options for the speed and feel of the timelapse but uses lots more data. A big advantage of the real time approach is I often split landscapes with a mask and have sky timelapse while the foreground remains normal speed. Very effective on shots where the wind is blowing trees which move at normal speed and the clouds race across the sky.
The big difference is you are not using long shutter times like on a stills camera with intervalometer can. So water blurs will look different.
For flicker I like the Digital Anarchy Flicker free OFX plugin best. I've got the Boris CC flicker fixer plus the one in Resolve Studio but Digital Anarchy seems to give the best results for timelapse.