The 2.5m Heatshield provides plenty, dont worry.
If your goal is to reduce mass: From Eve coming 75% ablator should be enough, you can even try 50%.
(Dont forget to remove monopropellant from the capsule if its your goal )
Thanks Snark for doing this, because i encountered similar problems recently. But both times i was able to find a workaround to finish my mission, thats why i havent posted the issues before.
Setup: I ve played 1000h+ in Ver. 1.0.X, recently i ve reinstalled my windows, so both cases happened with a fresh installed 1.2.X and a fresh started Career. Only Mods: KER and Chatterer. Dont think there are causing the problem but nothing is impossible (not even Kerbol SOI is the limit hihi)
Manned Kerbaled Vessel, Pod and Lab etc. with an attched landingprobe /w science in Duna orbit. A CommSat was also in Dunas orbit but behind the planet that time. Kerbaled Vessel had a relay antenna and connection to Kerbin, the CommSat not.
After detaching the probe which had only normal/nonrelay antennas with "short" range i had no controll over it. Kerbaled Vessel was only 100m away and wasnt relaying but was shown a connection to Kerbin. I just waited for my CommSat having connection again. That One made the connection, i landed the probe and got my SP.
Kerbaled Minmuslander, a service bay at bottom, inside a sciencerover to fetch data from surounding biomes. Landing stage had a relay antenna attached, the returncapsule a normal dish, the rover just a communutron 16. Some Commsats in range, didnt pay intension.
Detached the rover, visit nearby biomes, collect data, returned, scientist took the data and boarded.
Returned to Kerbin with the upper Capsule and left the landingstage behind. That had a probecore, battery and solar, also a relay antenna (extended ). Mission accomplished, no probs till now.
But a rover like that may be usefull in the future for contracts like "survey near (landingsite)...".
I quit playing that day. I started the game again.
Switched to the rover and had no controll. Landingvessel was 20m away. It had full EC, solar, core, relay antenna and connection to Kerbin (direct)
3+ CommSat in Range (sightline) but no con. Nessesary to point that all CommSat hat con. to Kerbin?
I now know that i cant steer the rover and will not accept any surveymissions. So no realproblem here.